ONLINE AMC 8 PREP WITH AOPS
Top scorers around the country use AoPS. Join training courses for beginners and advanced students.
VIEW CATALOG

Difference between revisions of "2002 AMC 8 Problems"

(Problem 14)
 
(37 intermediate revisions by 27 users not shown)
Line 1: Line 1:
 +
{{AMC8 Problems|year=2002|}}
 
==Problem 1==
 
==Problem 1==
  
A circle and two distinct lines are drawn on a sheet of paper. What is the largest possible number of points of intersection of these figures?
+
A [[circle]] and two distinct [[Line|lines]] are drawn on a sheet of paper. What is the largest possible number of points of intersection of these figures?
  
<math>\text{(A)}\ 2 \qquad \text{(B)}\ 3 \qquad \text{(C)}\ 4 \qquad \text{(D)}\ 5 \qquad \text{(E)}\ 6</math>
+
<math>\text {(A)}\ 2 \qquad \text {(B)}\ 3 \qquad {(C)}\ 4 \qquad {(D)}\ 5 \qquad {(E)}\ 6</math>
  
 
[[2002 AMC 8 Problems/Problem 1 | Solution]]
 
[[2002 AMC 8 Problems/Problem 1 | Solution]]
Line 9: Line 10:
 
==Problem 2==
 
==Problem 2==
  
How many different combinations of <dollar/>5 bills and <dollar/>2 bills can be used to make a total of <dollar/>17? Order does not matter in this problem.
+
How many different combinations of \$5 bills and \$2 bills can be used to make a total of \$17? Order does not matter in this problem.
  
 
<math>\text{(A)}\ 2 \qquad \text{(B)}\ 3 \qquad \text{(C)}\ 4 \qquad \text{(D)}\ 5 \qquad \text{(E)}\ 6</math>
 
<math>\text{(A)}\ 2 \qquad \text{(B)}\ 3 \qquad \text{(C)}\ 4 \qquad \text{(D)}\ 5 \qquad \text{(E)}\ 6</math>
Line 24: Line 25:
  
 
==Problem 4==
 
==Problem 4==
 
 
The year 2002 is a palindrome (a number that reads the same from left to right as it does from right to left). What is the product of the digits of the next year after 2002 that is a palindrome?
 
The year 2002 is a palindrome (a number that reads the same from left to right as it does from right to left). What is the product of the digits of the next year after 2002 that is a palindrome?
  
Line 43: Line 43:
 
A birdbath is designed to overflow so that it will be self-cleaning. Water flows in at the rate of 20 milliliters per minute and drains at the rate of 18 milliliters per minute. One of these graphs shows the volume of water in the birdbath during the filling time and continuing into the overflow time. Which one is it?
 
A birdbath is designed to overflow so that it will be self-cleaning. Water flows in at the rate of 20 milliliters per minute and drains at the rate of 18 milliliters per minute. One of these graphs shows the volume of water in the birdbath during the filling time and continuing into the overflow time. Which one is it?
  
{{image}}
+
[[Image:2002amc8prob6graph.png|center]]
  
 
<math>\text{(A)}\ \text{A} \qquad \text{(B)}\ \text{B} \qquad \text{(C)}\ \text{C} \qquad \text{(D)}\ \text{D} \qquad \text{(E)}\ \text{E}</math>
 
<math>\text{(A)}\ \text{A} \qquad \text{(B)}\ \text{B} \qquad \text{(C)}\ \text{C} \qquad \text{(D)}\ \text{D} \qquad \text{(E)}\ \text{E}</math>
Line 53: Line 53:
 
The students in Mrs. Sawyer's class were asked to do a taste test of five kinds of candy. Each student chose one kind of candy. A bar graph of their preferences is shown. What percent of her class chose candy E?
 
The students in Mrs. Sawyer's class were asked to do a taste test of five kinds of candy. Each student chose one kind of candy. A bar graph of their preferences is shown. What percent of her class chose candy E?
  
{{image}}
+
<asy>
 +
real[] r={6, 8, 4, 2, 5};
 +
int i;
 +
for(i=0; i<5; i=i+1) {
 +
filldraw((4i,0)--(4i+3,0)--(4i+3,2r[i])--(4i,2r[i])--cycle, black, black);
 +
}
 +
draw(origin--(19,0)--(19,16)--(0,16)--cycle, linewidth(0.9));
 +
for(i=1; i<8; i=i+1) {
 +
draw((0,2i)--(19,2i));
 +
}
 +
label("$0$", (0,2*0), W);
 +
label("$1$", (0,2*1), W);
 +
label("$2$", (0,2*2), W);
 +
label("$3$", (0,2*3), W);
 +
label("$4$", (0,2*4), W);
 +
label("$5$", (0,2*5), W);
 +
label("$6$", (0,2*6), W);
 +
label("$7$", (0,2*7), W);
 +
label("$8$", (0,2*8), W);
 +
label("$A$", (0*4+1.5, 0), S);
 +
label("$B$", (1*4+1.5, 0), S);
 +
label("$C$", (2*4+1.5, 0), S);
 +
label("$D$", (3*4+1.5, 0), S);
 +
label("$E$", (4*4+1.5, 0), S);
 +
label("SWEET TOOTH", (9.5,18), N);
 +
label("Kinds of candy", (9.5,-2), S);
 +
label(rotate(90)*"Number of students", (-2,8), W);</asy>
  
 
<math>\text{(A)}\ 5 \qquad \text{(B)}\ 12 \qquad \text{(C)}\ 15 \qquad \text{(D)}\ 16 \qquad \text{(E)}\ 20</math>
 
<math>\text{(A)}\ 5 \qquad \text{(B)}\ 12 \qquad \text{(C)}\ 15 \qquad \text{(D)}\ 16 \qquad \text{(E)}\ 20</math>
Line 68: Line 94:
 
</center>
 
</center>
  
{{image}}
+
<asy>
 +
/* AMC8 2002 #8, 9, 10 Problem */
 +
size(3inch, 1.5inch);
 +
for ( int y = 0; y &lt;= 5; ++y )
 +
{
 +
draw((0,y)--(18,y));
 +
}
 +
draw((0,0)--(0,5));
 +
draw((6,0)--(6,5));
 +
draw((9,0)--(9,5));
 +
draw((12,0)--(12,5));
 +
draw((15,0)--(15,5));
 +
draw((18,0)--(18,5));
 +
draw(scale(0.8)*"50s", (7.5,4.5));
 +
draw(scale(0.8)*"4", (7.5,3.5));
 +
draw(scale(0.8)*"8", (7.5,2.5));
 +
draw(scale(0.8)*"6", (7.5,1.5));
 +
draw(scale(0.8)*"3", (7.5,0.5));
 +
draw(scale(0.8)*"60s", (10.5,4.5));
 +
draw(scale(0.8)*"7", (10.5,3.5));
 +
draw(scale(0.8)*"4", (10.5,2.5));
 +
draw(scale(0.8)*"4", (10.5,1.5));
 +
draw(scale(0.8)*"9", (10.5,0.5));
 +
draw(scale(0.8)*"70s", (13.5,4.5));
 +
draw(scale(0.8)*"12", (13.5,3.5));
 +
draw(scale(0.8)*"12", (13.5,2.5));
 +
draw(scale(0.8)*"6", (13.5,1.5));
 +
draw(scale(0.8)*"13", (13.5,0.5));
 +
draw(scale(0.8)*"80s", (16.5,4.5));
 +
draw(scale(0.8)*"8", (16.5,3.5));
 +
draw(scale(0.8)*"15", (16.5,2.5));
 +
draw(scale(0.8)*"10", (16.5,1.5));
 +
draw(scale(0.8)*"9", (16.5,0.5));
 +
label(scale(0.8)*"Country", (3,4.5));
 +
label(scale(0.8)*"Brazil", (3,3.5));
 +
label(scale(0.8)*"France", (3,2.5));
 +
label(scale(0.8)*"Peru", (3,1.5));
 +
label(scale(0.8)*"Spain", (3,0.5));
 +
label(scale(0.9)*"Juan's Stamp Collection", (9,0), S);
 +
label(scale(0.9)*"Number of Stamps by Decade", (9,5), N);</asy>
  
 
===Problem 8===
 
===Problem 8===
Line 80: Line 145:
 
===Problem 9===
 
===Problem 9===
  
His South American stamps issued before the '70s cost him
+
His South American stamps issued before the ‘70s cost him
  
 
<math>\text{(A)}\ \textdollar 0.40 \qquad \text{(B)}\ \textdollar 1.06 \qquad \text{(C)}\ \textdollar 1.80 \qquad \text{(D)}\ \textdollar 2.38 \qquad \text{(E)}\ \textdollar 2.64</math>
 
<math>\text{(A)}\ \textdollar 0.40 \qquad \text{(B)}\ \textdollar 1.06 \qquad \text{(C)}\ \textdollar 1.80 \qquad \text{(D)}\ \textdollar 2.38 \qquad \text{(E)}\ \textdollar 2.64</math>
Line 98: Line 163:
 
A sequence of squares is made of identical square tiles. The edge of each square is one tile length longer than the edge of the previous square. The first three squares are shown. How many more tiles does the seventh square require than the sixth?
 
A sequence of squares is made of identical square tiles. The edge of each square is one tile length longer than the edge of the previous square. The first three squares are shown. How many more tiles does the seventh square require than the sixth?
  
{{image}}
+
<asy>
 +
path p=origin--(1,0)--(1,1)--(0,1)--cycle;
 +
draw(p);
 +
draw(shift(3,0)*p);
 +
draw(shift(3,1)*p);
 +
draw(shift(4,0)*p);
 +
draw(shift(4,1)*p);
 +
draw(shift(7,0)*p);
 +
draw(shift(7,1)*p);
 +
draw(shift(7,2)*p);
 +
draw(shift(8,0)*p);
 +
draw(shift(8,1)*p);
 +
draw(shift(8,2)*p);
 +
draw(shift(9,0)*p);
 +
draw(shift(9,1)*p);
 +
draw(shift(9,2)*p);</asy>
  
 
<math>\text{(A)}\ 11 \qquad \text{(B)}\ 12 \qquad \text{(C)}\ 13 \qquad \text{(D)}\ 14 \qquad \text{(E)}\ 15</math>
 
<math>\text{(A)}\ 11 \qquad \text{(B)}\ 12 \qquad \text{(C)}\ 13 \qquad \text{(D)}\ 14 \qquad \text{(E)}\ 15</math>
Line 107: Line 187:
  
 
A board game spinner is divided into three regions labeled <math>A</math>, <math>B</math> and <math>C</math>. The probability of the arrow stopping on region <math>A</math> is <math>\frac{1}{3}</math> and on region <math>B</math> is <math>\frac{1}{2}</math>. The probability of the arrow stopping on region <math>C</math> is
 
A board game spinner is divided into three regions labeled <math>A</math>, <math>B</math> and <math>C</math>. The probability of the arrow stopping on region <math>A</math> is <math>\frac{1}{3}</math> and on region <math>B</math> is <math>\frac{1}{2}</math>. The probability of the arrow stopping on region <math>C</math> is
 
{{image}}
 
  
 
<math>\text{(A)}\ \frac{1}{12} \qquad \text{(B)}\ \frac{1}{6} \qquad \text{(C)}\ \frac{1}{5} \qquad \text{(D)}\ \frac{1}{3} \qquad \text{(E)}\ \frac{2}{5}</math>
 
<math>\text{(A)}\ \frac{1}{12} \qquad \text{(B)}\ \frac{1}{6} \qquad \text{(C)}\ \frac{1}{5} \qquad \text{(D)}\ \frac{1}{3} \qquad \text{(E)}\ \frac{2}{5}</math>
Line 124: Line 202:
 
==Problem 14==
 
==Problem 14==
  
A merchant offers a large group of items at 30% off. Later, the merchant takes 20% off these sale prices and claims that the final price of these items is 50% off the original price. The total discount is
+
A merchant offers a large group of items at 30% off. Later, the merchant takes 20% off these sale prices. The total discount is
  
<math>\text{(A)}\ 35\% \qquad \text{(B)}\ 44\% \qquad \text{(C)}\ 50\% \qquad \text{(D)}\ 56\% \text{(E)}\ 60\%</math>
+
<math>\text{(A)}\ 35\% \qquad \text{(B)}\ 44\% \qquad \text{(C)}\ 50\% \qquad \text{(D)}\ 56\% \qquad \text{(E)}\ 60\%</math>
  
 
[[2002 AMC 8 Problems/Problem 14 | Solution]]
 
[[2002 AMC 8 Problems/Problem 14 | Solution]]
  
 
==Problem 15==
 
==Problem 15==
 +
 +
Which of the following polygons has the largest area?
 +
 +
<asy>
 +
size(330);
 +
int i,j,k;
 +
for(i=0;i<5; i=i+1) {
 +
for(j=0;j<5;j=j+1) {
 +
for(k=0;k<5;k=k+1) {
 +
dot((6i+j, k));
 +
}}}
 +
draw((0,0)--(4,0)--(3,1)--(3,3)--(2,3)--(2,1)--(1,1)--cycle);
 +
draw(shift(6,0)*((0,0)--(4,0)--(4,1)--(3,1)--(3,2)--(2,1)--(1,1)--(0,2)--cycle));
 +
draw(shift(12,0)*((0,1)--(1,0)--(3,2)--(3,3)--(1,1)--(1,3)--(0,4)--cycle));
 +
draw(shift(18,0)*((0,1)--(2,1)--(3,0)--(3,3)--(2,2)--(1,3)--(1,2)--(0,2)--cycle));
 +
draw(shift(24,0)*((1,0)--(2,1)--(2,3)--(3,2)--(3,4)--(0,4)--(1,3)--cycle));
 +
label("$A$", (0*6+2, 0), S);
 +
label("$B$", (1*6+2, 0), S);
 +
label("$C$", (2*6+2, 0), S);
 +
label("$D$", (3*6+2, 0), S);
 +
label("$E$", (4*6+2, 0), S);</asy>
 +
 +
<math>\text{(A)} \text{A} \qquad \text{(B)}\ \text{B} \qquad \text{(C)}\ \text{C} \qquad \text{(D)}\ \text{D} \qquad \text{(E)}\ \text{E}</math>
  
 
[[2002 AMC 8 Problems/Problem 15 | Solution]]
 
[[2002 AMC 8 Problems/Problem 15 | Solution]]
  
 
==Problem 16==
 
==Problem 16==
 +
 +
Right isosceles triangles are constructed on the sides of a 3-4-5 right triangle, as shown. A capital letter represents the area of each triangle. Which one of the following is true?
 +
 +
<asy>/* AMC8 2002 #16 Problem */
 +
draw((0,0)--(4,0)--(4,3)--cycle);
 +
draw((4,3)--(-4,4)--(0,0));
 +
draw((-0.15,0.1)--(0,0.25)--(.15,0.1));
 +
draw((0,0)--(4,-4)--(4,0));
 +
draw((4,0.2)--(3.8,0.2)--(3.8,-0.2)--(4,-0.2));
 +
draw((4,0)--(7,3)--(4,3));
 +
draw((4,2.8)--(4.2,2.8)--(4.2,3));
 +
label(scale(0.8)*"$Z$", (0, 3), S);
 +
label(scale(0.8)*"$Y$", (3,-2));
 +
label(scale(0.8)*"$X$", (5.5, 2.5));
 +
label(scale(0.8)*"$W$", (2.6,1));
 +
label(scale(0.65)*"5", (2,2));
 +
label(scale(0.65)*"4", (2.3,-0.4));
 +
label(scale(0.65)*"3", (4.3,1.5));</asy>
 +
 +
<math>\text{(A)}\ X + Z = W + Y \qquad \text{(B)}\ W + X = Z \qquad \text{(C)}\ 3X + 4Y = 5Z</math>
 +
 +
<math>\text{(D)}\ X +W = \frac{1}{2} (Y + Z) \qquad \text{(E)}\ X + Y = Z</math>
  
 
[[2002 AMC 8 Problems/Problem 16 | Solution]]
 
[[2002 AMC 8 Problems/Problem 16 | Solution]]
  
 
==Problem 17==
 
==Problem 17==
 +
 +
In a mathematics contest with ten problems, a student gains 5 points for a correct answer and loses 2 points for an incorrect answer. If Olivia answered every problem and her score was 29, how many correct answers did she have?
 +
 +
<math>\text{(A)}\ 5 \qquad \text{(B)}\ 6 \qquad \text{(C)}\ 7 \qquad \text{(D)}\ 8 \qquad \text{(E)}\ 9</math>
  
 
[[2002 AMC 8 Problems/Problem 17 | Solution]]
 
[[2002 AMC 8 Problems/Problem 17 | Solution]]
  
 
==Problem 18==
 
==Problem 18==
 +
 +
Vincent skated 1 hr 15 min each day for 5 days and 1 hr 30 min each day for 3 days. How long would he have to skate the ninth day in order to average 85 minutes of skating each day for the entire time?
 +
 +
<math>\text{(A)}\ \text{1 hr} \qquad \text{(B)}\ \text{1 hr 10 min} \qquad \text{(C)}\ \text{1 hr 20 min} \qquad \text{(D)}\ \text{1 hr 40 min} \qquad \text{(E)}\ \text{2 hr}</math>
  
 
[[2002 AMC 8 Problems/Problem 18 | Solution]]
 
[[2002 AMC 8 Problems/Problem 18 | Solution]]
  
 
==Problem 19==
 
==Problem 19==
 +
 +
How many whole numbers between 99 and 999 contain exactly one 0?
 +
 +
<math>\text{(A)}\ 72 \qquad \text{(B)}\ 90 \qquad \text{(C)}\ 144 \qquad \text{(D)}\ 162 \qquad \text{(E)}\ 180</math>
  
 
[[2002 AMC 8 Problems/Problem 19 | Solution]]
 
[[2002 AMC 8 Problems/Problem 19 | Solution]]
  
 
==Problem 20==
 
==Problem 20==
 +
 +
The area of triangle <math>XYZ</math> is 8 square inches. Points <math>A</math> and <math>B</math> are midpoints of congruent segments <math>\overline{XY}</math> and <math>\overline{XZ}</math>. Altitude <math>\overline{XC}</math> bisects <math>\overline{YZ}</math>. The area (in square inches) of the shaded region is
 +
 +
<asy>/* AMC8 2002 #20 Problem */
 +
fill((0,0)--(2.5,2)--(5,2)--(5,0)--cycle, mediumgrey);
 +
draw((0,0)--(10,0)--(5,4)--cycle);
 +
draw((2.5,2)--(7.5,2));
 +
draw((5,4)--(5,0));
 +
label(scale(0.8)*"$X$", (5,4), N);
 +
label(scale(0.8)*"$Y$", (0,0), W);
 +
label(scale(0.8)*"$Z$", (10,0), E);
 +
label(scale(0.8)*"$A$", (2.5,2.2), W);
 +
label(scale(0.8)*"$B$", (7.5,2.2), E);
 +
label(scale(0.8)*"$C$", (5,0), S);
 +
fill((0,-.8)--(1,-.8)--(1,-.95)--cycle, white);</asy>
 +
 +
<math>\text{(A)}\ 1\frac{1}{2} \qquad \text{(B)}\ 2 \qquad \text{(C)}\ 2\frac{1}{2} \qquad \text{(D)}\ 3 \qquad \text{(E)}\ 3\frac{1}{2}</math>
  
 
[[2002 AMC 8 Problems/Problem 20 | Solution]]
 
[[2002 AMC 8 Problems/Problem 20 | Solution]]
  
 
==Problem 21==
 
==Problem 21==
 +
 +
Harold tosses a nickel four times. The probability that he gets at least as many heads as tails is
 +
 +
<math>\text{(A)}\ \frac{5}{16} \qquad \text{(B)}\ \frac{3}{8} \qquad \text{(C)}\ \frac{1}{2} \qquad \text{(D)}\ \frac{5}{8} \qquad \text{(E)}\ \frac{11}{16}</math>
  
 
[[2002 AMC 8 Problems/Problem 21 | Solution]]
 
[[2002 AMC 8 Problems/Problem 21 | Solution]]
  
 
==Problem 22==
 
==Problem 22==
 +
 +
Six cubes, each an inch on an edge, are fastened together, as shown. Find the total surface area in square inches. Include the top, bottom and sides.
 +
 +
<asy>/* AMC8 2002 #22 Problem */
 +
draw((0,0)--(0,1)--(1,1)--(1,0)--cycle);
 +
draw((0,1)--(0.5,1.5)--(1.5,1.5)--(1,1));
 +
draw((1,0)--(1.5,0.5)--(1.5,1.5));
 +
draw((0.5,1.5)--(1,2)--(1.5,2));
 +
draw((1.5,1.5)--(1.5,3.5)--(2,4)--(3,4)--(2.5,3.5)--(2.5,0.5)--(1.5,.5));
 +
draw((1.5,3.5)--(2.5,3.5));
 +
draw((1.5,1.5)--(3.5,1.5)--(3.5,2.5)--(1.5,2.5));
 +
draw((3,4)--(3,3)--(2.5,2.5));
 +
draw((3,3)--(4,3)--(4,2)--(3.5,1.5));
 +
draw((4,3)--(3.5,2.5));
 +
draw((2.5,.5)--(3,1)--(3,1.5));</asy>
 +
 +
<math>\text{(A)}\ 18 \qquad \text{(B)}\ 24 \qquad \text{(C)}\ 26 \qquad \text{(D)}\ 30 \qquad \text{(E)}\ 36</math>
  
 
[[2002 AMC 8 Problems/Problem 22 | Solution]]
 
[[2002 AMC 8 Problems/Problem 22 | Solution]]
  
 
==Problem 23==
 
==Problem 23==
 +
 +
A corner of a tiled floor is shown. If the entire floor is tiled in this way and each of the four corners looks like this one, then what fraction of the tiled floor is made of
 +
darker tiles?
 +
 +
<asy>/* AMC8 2002 #23 Problem */
 +
fill((0,2)--(1,3)--(2,3)--(2,4)--(3,5)--(4,4)--(4,3)--(5,3)--(6,2)--(5,1)--(4,1)--(4,0)--(2,0)--(2,1)--(1,1)--cycle, mediumgrey);
 +
fill((7,1)--(6,2)--(7,3)--(8,3)--(8,4)--(9,5)--(10,4)--(7,0)--cycle, mediumgrey);
 +
fill((3,5)--(2,6)--(2,7)--(1,7)--(0,8)--(1,9)--(2,9)--(2,10)--(3,11)--(4,10)--(4,9)--(5,9)--(6,8)--(5,7)--(4,7)--(4,6)--cycle, mediumgrey);
 +
fill((6,8)--(7,9)--(8,9)--(8,10)--(9,11)--(10,10)--(10,9)--(11,9)--(11,7)--(10,7)--(10,6)--(9,5)--(8,6)--(8,7)--(7,7)--cycle, mediumgrey);
 +
 +
draw((0,0)--(0,11)--(11,11));
 +
for ( int x = 1; x &lt; 11; ++x )
 +
{
 +
    draw((x,11)--(x,0), linetype("4 4"));
 +
}
 +
 +
for ( int y = 1; y &lt; 11; ++y )
 +
{
 +
    draw((0,y)--(11,y), linetype("4 4"));
 +
}
 +
clip((0,0)--(0,11)--(11,11)--(11,5)--(4,1)--cycle);</asy>
 +
 +
<math>\text{(A)}\ \frac{1}{3} \qquad \text{(B)}\ \frac{4}{9} \qquad \text{(C)}\ \frac{1}{2} \qquad \text{(D)}\ \frac{5}{9} \qquad \text{(E)}\ \frac{5}{8}</math>
  
 
[[2002 AMC 8 Problems/Problem 23 | Solution]]
 
[[2002 AMC 8 Problems/Problem 23 | Solution]]
  
 
==Problem 24==
 
==Problem 24==
 +
 +
Miki has a dozen oranges of the same size and a dozen pears of the same size. Miki uses her juicer to extract 8 ounces of pear juice from 3 pears and 8 ounces of orange juice from 2 oranges. She makes a pear-orange juice blend from an equal number of pears and oranges. What percent of the blend is pear juice?
 +
 +
<math>\text{(A)}\ 30 \qquad \text{(B)}\ 40 \qquad \text{(C)}\ 50 \qquad \text{(D)}\ 60 \qquad \text{(E)}\ 70</math>
  
 
[[2002 AMC 8 Problems/Problem 24 | Solution]]
 
[[2002 AMC 8 Problems/Problem 24 | Solution]]
  
 
==Problem 25==
 
==Problem 25==
 +
 +
Loki, Moe, Nick and Ott are good friends. Ott had no money, but the others did. Moe gave Ott one-fifth of his money, Loki gave Ott one-fourth of his money and Nick gave Ott one-third of his money. Each gave Ott the same amount of money. What fractional part of the group's money does Ott now have?
 +
 +
<math>\text{(A)}\ \frac{1}{10} \qquad \text{(B)}\ \frac{1}{4} \qquad \text{(C)}\ \frac{1}{3} \qquad \text{(D)}\ \frac{2}{5} \qquad \text{(E)}\ \frac{1}{2}</math>
  
 
[[2002 AMC 8 Problems/Problem 25 | Solution]]
 
[[2002 AMC 8 Problems/Problem 25 | Solution]]
Line 178: Line 382:
 
* [[AMC 8]]
 
* [[AMC 8]]
 
* [[AMC 8 Problems and Solutions]]
 
* [[AMC 8 Problems and Solutions]]
* [[Mathematics competition resources]]
+
* [[Mathematics competition resources|Mathematics Competition Resources]]
 +
 
 +
 
 +
{{MAA Notice}}

Latest revision as of 00:17, 1 October 2024

2002 AMC 8 (Answer Key)
Printable versions: WikiAoPS ResourcesPDF

Instructions

  1. This is a 25-question, multiple choice test. Each question is followed by answers marked A, B, C, D and E. Only one of these is correct.
  2. You will receive 1 point for each correct answer. There is no penalty for wrong answers.
  3. No aids are permitted other than plain scratch paper, writing utensils, ruler, and erasers. In particular, graph paper, compass, protractor, calculators, computers, smartwatches, and smartphones are not permitted. Rules
  4. Figures are not necessarily drawn to scale.
  5. You will have 40 minutes working time to complete the test.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

Problem 1

A circle and two distinct lines are drawn on a sheet of paper. What is the largest possible number of points of intersection of these figures?

$\text {(A)}\ 2 \qquad \text {(B)}\ 3 \qquad {(C)}\ 4 \qquad {(D)}\ 5 \qquad {(E)}\ 6$

Solution

Problem 2

How many different combinations of $5 bills and $2 bills can be used to make a total of $17? Order does not matter in this problem.

$\text{(A)}\ 2 \qquad \text{(B)}\ 3 \qquad \text{(C)}\ 4 \qquad \text{(D)}\ 5 \qquad \text{(E)}\ 6$

Solution

Problem 3

What is the smallest possible average of four distinct positive even integers?

$\text{(A)}\ 3 \qquad \text{(B)}\ 4 \qquad \text{(C)}\ 5 \qquad \text{(D)}\ 6 \qquad \text{(E)}\ 7$

Solution

Problem 4

The year 2002 is a palindrome (a number that reads the same from left to right as it does from right to left). What is the product of the digits of the next year after 2002 that is a palindrome?

$\text{(A)}\ 0 \qquad \text{(B)}\ 4 \qquad \text{(C)}\ 9 \qquad \text{(D)}\ 16 \qquad \text{(E)}\ 25$

Solution

Problem 5

Carlos Montado was born on Saturday, November 9, 2002. On what day of the week will Carlos be 706 days old?

$\text{(A)}\ \text{Monday} \qquad \text{(B)}\ \text{Wednesday} \qquad \text{(C)}\ \text{Friday} \qquad \text{(D)}\ \text{Saturday} \qquad \text{(E)}\ \text{Sunday}$

Solution

Problem 6

A birdbath is designed to overflow so that it will be self-cleaning. Water flows in at the rate of 20 milliliters per minute and drains at the rate of 18 milliliters per minute. One of these graphs shows the volume of water in the birdbath during the filling time and continuing into the overflow time. Which one is it?

2002amc8prob6graph.png

$\text{(A)}\ \text{A} \qquad \text{(B)}\ \text{B} \qquad \text{(C)}\ \text{C} \qquad \text{(D)}\ \text{D} \qquad \text{(E)}\ \text{E}$

Solution

Problem 7

The students in Mrs. Sawyer's class were asked to do a taste test of five kinds of candy. Each student chose one kind of candy. A bar graph of their preferences is shown. What percent of her class chose candy E?

[asy] real[] r={6, 8, 4, 2, 5}; int i; for(i=0; i<5; i=i+1) { filldraw((4i,0)--(4i+3,0)--(4i+3,2r[i])--(4i,2r[i])--cycle, black, black); } draw(origin--(19,0)--(19,16)--(0,16)--cycle, linewidth(0.9)); for(i=1; i<8; i=i+1) { draw((0,2i)--(19,2i)); } label("$0$", (0,2*0), W); label("$1$", (0,2*1), W); label("$2$", (0,2*2), W); label("$3$", (0,2*3), W); label("$4$", (0,2*4), W); label("$5$", (0,2*5), W); label("$6$", (0,2*6), W); label("$7$", (0,2*7), W); label("$8$", (0,2*8), W); label("$A$", (0*4+1.5, 0), S); label("$B$", (1*4+1.5, 0), S); label("$C$", (2*4+1.5, 0), S); label("$D$", (3*4+1.5, 0), S); label("$E$", (4*4+1.5, 0), S); label("SWEET TOOTH", (9.5,18), N); label("Kinds of candy", (9.5,-2), S); label(rotate(90)*"Number of students", (-2,8), W);[/asy]

$\text{(A)}\ 5 \qquad \text{(B)}\ 12 \qquad \text{(C)}\ 15 \qquad \text{(D)}\ 16 \qquad \text{(E)}\ 20$

Solution

Juan's Old Stamping Grounds

Problems 8,9 and 10 use the data found in the accompanying paragraph and table:

Juan organizes the stamps in his collection by country and by the decade in which they were issued. The prices he paid for them at a stamp shop were: Brazil and France, 6 cents each, Peru 4 cents each, and Spain 5 cents each. (Brazil and Peru are South American countries and France and Spain are in Europe.)

[asy] /* AMC8 2002 #8, 9, 10 Problem */ size(3inch, 1.5inch); for ( int y = 0; y &lt;= 5; ++y ) { draw((0,y)--(18,y)); } draw((0,0)--(0,5)); draw((6,0)--(6,5)); draw((9,0)--(9,5)); draw((12,0)--(12,5)); draw((15,0)--(15,5)); draw((18,0)--(18,5)); draw(scale(0.8)*"50s", (7.5,4.5)); draw(scale(0.8)*"4", (7.5,3.5)); draw(scale(0.8)*"8", (7.5,2.5)); draw(scale(0.8)*"6", (7.5,1.5)); draw(scale(0.8)*"3", (7.5,0.5)); draw(scale(0.8)*"60s", (10.5,4.5)); draw(scale(0.8)*"7", (10.5,3.5)); draw(scale(0.8)*"4", (10.5,2.5)); draw(scale(0.8)*"4", (10.5,1.5)); draw(scale(0.8)*"9", (10.5,0.5)); draw(scale(0.8)*"70s", (13.5,4.5)); draw(scale(0.8)*"12", (13.5,3.5)); draw(scale(0.8)*"12", (13.5,2.5)); draw(scale(0.8)*"6", (13.5,1.5)); draw(scale(0.8)*"13", (13.5,0.5)); draw(scale(0.8)*"80s", (16.5,4.5)); draw(scale(0.8)*"8", (16.5,3.5)); draw(scale(0.8)*"15", (16.5,2.5)); draw(scale(0.8)*"10", (16.5,1.5)); draw(scale(0.8)*"9", (16.5,0.5)); label(scale(0.8)*"Country", (3,4.5)); label(scale(0.8)*"Brazil", (3,3.5)); label(scale(0.8)*"France", (3,2.5)); label(scale(0.8)*"Peru", (3,1.5)); label(scale(0.8)*"Spain", (3,0.5)); label(scale(0.9)*"Juan's Stamp Collection", (9,0), S); label(scale(0.9)*"Number of Stamps by Decade", (9,5), N);[/asy]

Problem 8

How many of his European stamps were issued in the '80s?

$\text{(A)}\ 9 \qquad \text{(B)}\ 15 \qquad \text{(C)}\ 18 \qquad \text{(D)}\ 24 \qquad \text{(E)}\ 42$

Solution

Problem 9

His South American stamps issued before the ‘70s cost him

$\text{(A)}\ \textdollar 0.40 \qquad \text{(B)}\ \textdollar 1.06 \qquad \text{(C)}\ \textdollar 1.80 \qquad \text{(D)}\ \textdollar 2.38 \qquad \text{(E)}\ \textdollar 2.64$

Solution

Problem 10

The average price of his '70s stamps is closest to

$\text{(A)}\ 3.5 \text{ cents} \qquad \text{(B)}\ 4 \text{ cents} \qquad \text{(C)}\ 4.5 \text{ cents} \qquad \text{(D)}\ 5 \text{ cents} \qquad \text{(E)}\ 5.5 \text{ cents}$

Solution

Problem 11

A sequence of squares is made of identical square tiles. The edge of each square is one tile length longer than the edge of the previous square. The first three squares are shown. How many more tiles does the seventh square require than the sixth?

[asy] path p=origin--(1,0)--(1,1)--(0,1)--cycle; draw(p); draw(shift(3,0)*p); draw(shift(3,1)*p); draw(shift(4,0)*p); draw(shift(4,1)*p); draw(shift(7,0)*p); draw(shift(7,1)*p); draw(shift(7,2)*p); draw(shift(8,0)*p); draw(shift(8,1)*p); draw(shift(8,2)*p); draw(shift(9,0)*p); draw(shift(9,1)*p); draw(shift(9,2)*p);[/asy]

$\text{(A)}\ 11 \qquad \text{(B)}\ 12 \qquad \text{(C)}\ 13 \qquad \text{(D)}\ 14 \qquad \text{(E)}\ 15$

Solution

Problem 12

A board game spinner is divided into three regions labeled $A$, $B$ and $C$. The probability of the arrow stopping on region $A$ is $\frac{1}{3}$ and on region $B$ is $\frac{1}{2}$. The probability of the arrow stopping on region $C$ is

$\text{(A)}\ \frac{1}{12} \qquad \text{(B)}\ \frac{1}{6} \qquad \text{(C)}\ \frac{1}{5} \qquad \text{(D)}\ \frac{1}{3} \qquad \text{(E)}\ \frac{2}{5}$

Solution

Problem 13

For his birthday, Bert gets a box that holds 125 jellybeans when filled to capacity. A few weeks later, Carrie gets a larger box full of jellybeans. Her box is twice as high, twice as wide and twice as long as Bert's. Approximately, how many jellybeans did Carrie get?

$\text{(A)}\ 250 \qquad \text{(B)}\ 500 \qquad \text{(C)}\ 625 \qquad \text{(D)}\ 750 \qquad \text{(E)}\ 1000$

Solution

Problem 14

A merchant offers a large group of items at 30% off. Later, the merchant takes 20% off these sale prices. The total discount is

$\text{(A)}\ 35\% \qquad \text{(B)}\ 44\% \qquad \text{(C)}\ 50\% \qquad \text{(D)}\ 56\% \qquad \text{(E)}\ 60\%$

Solution

Problem 15

Which of the following polygons has the largest area?

[asy] size(330); int i,j,k; for(i=0;i<5; i=i+1) { for(j=0;j<5;j=j+1) { for(k=0;k<5;k=k+1) { dot((6i+j, k)); }}} draw((0,0)--(4,0)--(3,1)--(3,3)--(2,3)--(2,1)--(1,1)--cycle); draw(shift(6,0)*((0,0)--(4,0)--(4,1)--(3,1)--(3,2)--(2,1)--(1,1)--(0,2)--cycle)); draw(shift(12,0)*((0,1)--(1,0)--(3,2)--(3,3)--(1,1)--(1,3)--(0,4)--cycle)); draw(shift(18,0)*((0,1)--(2,1)--(3,0)--(3,3)--(2,2)--(1,3)--(1,2)--(0,2)--cycle)); draw(shift(24,0)*((1,0)--(2,1)--(2,3)--(3,2)--(3,4)--(0,4)--(1,3)--cycle)); label("$A$", (0*6+2, 0), S); label("$B$", (1*6+2, 0), S); label("$C$", (2*6+2, 0), S); label("$D$", (3*6+2, 0), S); label("$E$", (4*6+2, 0), S);[/asy]

$\text{(A)} \text{A} \qquad \text{(B)}\ \text{B} \qquad \text{(C)}\ \text{C} \qquad \text{(D)}\ \text{D} \qquad \text{(E)}\ \text{E}$

Solution

Problem 16

Right isosceles triangles are constructed on the sides of a 3-4-5 right triangle, as shown. A capital letter represents the area of each triangle. Which one of the following is true?

[asy]/* AMC8 2002 #16 Problem */ draw((0,0)--(4,0)--(4,3)--cycle); draw((4,3)--(-4,4)--(0,0)); draw((-0.15,0.1)--(0,0.25)--(.15,0.1)); draw((0,0)--(4,-4)--(4,0)); draw((4,0.2)--(3.8,0.2)--(3.8,-0.2)--(4,-0.2)); draw((4,0)--(7,3)--(4,3)); draw((4,2.8)--(4.2,2.8)--(4.2,3)); label(scale(0.8)*"$Z$", (0, 3), S); label(scale(0.8)*"$Y$", (3,-2)); label(scale(0.8)*"$X$", (5.5, 2.5)); label(scale(0.8)*"$W$", (2.6,1)); label(scale(0.65)*"5", (2,2)); label(scale(0.65)*"4", (2.3,-0.4)); label(scale(0.65)*"3", (4.3,1.5));[/asy]

$\text{(A)}\ X + Z = W + Y \qquad \text{(B)}\ W + X = Z \qquad \text{(C)}\ 3X + 4Y = 5Z$

$\text{(D)}\ X +W = \frac{1}{2} (Y + Z) \qquad \text{(E)}\ X + Y = Z$

Solution

Problem 17

In a mathematics contest with ten problems, a student gains 5 points for a correct answer and loses 2 points for an incorrect answer. If Olivia answered every problem and her score was 29, how many correct answers did she have?

$\text{(A)}\ 5 \qquad \text{(B)}\ 6 \qquad \text{(C)}\ 7 \qquad \text{(D)}\ 8 \qquad \text{(E)}\ 9$

Solution

Problem 18

Vincent skated 1 hr 15 min each day for 5 days and 1 hr 30 min each day for 3 days. How long would he have to skate the ninth day in order to average 85 minutes of skating each day for the entire time?

$\text{(A)}\ \text{1 hr} \qquad \text{(B)}\ \text{1 hr 10 min} \qquad \text{(C)}\ \text{1 hr 20 min} \qquad \text{(D)}\ \text{1 hr 40 min} \qquad \text{(E)}\ \text{2 hr}$

Solution

Problem 19

How many whole numbers between 99 and 999 contain exactly one 0?

$\text{(A)}\ 72 \qquad \text{(B)}\ 90 \qquad \text{(C)}\ 144 \qquad \text{(D)}\ 162 \qquad \text{(E)}\ 180$

Solution

Problem 20

The area of triangle $XYZ$ is 8 square inches. Points $A$ and $B$ are midpoints of congruent segments $\overline{XY}$ and $\overline{XZ}$. Altitude $\overline{XC}$ bisects $\overline{YZ}$. The area (in square inches) of the shaded region is

[asy]/* AMC8 2002 #20 Problem */ fill((0,0)--(2.5,2)--(5,2)--(5,0)--cycle, mediumgrey); draw((0,0)--(10,0)--(5,4)--cycle); draw((2.5,2)--(7.5,2)); draw((5,4)--(5,0)); label(scale(0.8)*"$X$", (5,4), N); label(scale(0.8)*"$Y$", (0,0), W); label(scale(0.8)*"$Z$", (10,0), E); label(scale(0.8)*"$A$", (2.5,2.2), W); label(scale(0.8)*"$B$", (7.5,2.2), E); label(scale(0.8)*"$C$", (5,0), S); fill((0,-.8)--(1,-.8)--(1,-.95)--cycle, white);[/asy]

$\text{(A)}\ 1\frac{1}{2} \qquad \text{(B)}\ 2 \qquad \text{(C)}\ 2\frac{1}{2} \qquad \text{(D)}\ 3 \qquad \text{(E)}\ 3\frac{1}{2}$

Solution

Problem 21

Harold tosses a nickel four times. The probability that he gets at least as many heads as tails is

$\text{(A)}\ \frac{5}{16} \qquad \text{(B)}\ \frac{3}{8} \qquad \text{(C)}\ \frac{1}{2} \qquad \text{(D)}\ \frac{5}{8} \qquad \text{(E)}\ \frac{11}{16}$

Solution

Problem 22

Six cubes, each an inch on an edge, are fastened together, as shown. Find the total surface area in square inches. Include the top, bottom and sides.

[asy]/* AMC8 2002 #22 Problem */ draw((0,0)--(0,1)--(1,1)--(1,0)--cycle); draw((0,1)--(0.5,1.5)--(1.5,1.5)--(1,1)); draw((1,0)--(1.5,0.5)--(1.5,1.5)); draw((0.5,1.5)--(1,2)--(1.5,2)); draw((1.5,1.5)--(1.5,3.5)--(2,4)--(3,4)--(2.5,3.5)--(2.5,0.5)--(1.5,.5)); draw((1.5,3.5)--(2.5,3.5)); draw((1.5,1.5)--(3.5,1.5)--(3.5,2.5)--(1.5,2.5)); draw((3,4)--(3,3)--(2.5,2.5)); draw((3,3)--(4,3)--(4,2)--(3.5,1.5)); draw((4,3)--(3.5,2.5)); draw((2.5,.5)--(3,1)--(3,1.5));[/asy]

$\text{(A)}\ 18 \qquad \text{(B)}\ 24 \qquad \text{(C)}\ 26 \qquad \text{(D)}\ 30 \qquad \text{(E)}\ 36$

Solution

Problem 23

A corner of a tiled floor is shown. If the entire floor is tiled in this way and each of the four corners looks like this one, then what fraction of the tiled floor is made of darker tiles?

[asy]/* AMC8 2002 #23 Problem */ fill((0,2)--(1,3)--(2,3)--(2,4)--(3,5)--(4,4)--(4,3)--(5,3)--(6,2)--(5,1)--(4,1)--(4,0)--(2,0)--(2,1)--(1,1)--cycle, mediumgrey); fill((7,1)--(6,2)--(7,3)--(8,3)--(8,4)--(9,5)--(10,4)--(7,0)--cycle, mediumgrey); fill((3,5)--(2,6)--(2,7)--(1,7)--(0,8)--(1,9)--(2,9)--(2,10)--(3,11)--(4,10)--(4,9)--(5,9)--(6,8)--(5,7)--(4,7)--(4,6)--cycle, mediumgrey); fill((6,8)--(7,9)--(8,9)--(8,10)--(9,11)--(10,10)--(10,9)--(11,9)--(11,7)--(10,7)--(10,6)--(9,5)--(8,6)--(8,7)--(7,7)--cycle, mediumgrey);  draw((0,0)--(0,11)--(11,11)); for ( int x = 1; x &lt; 11; ++x ) {     draw((x,11)--(x,0), linetype("4 4")); }  for ( int y = 1; y &lt; 11; ++y ) {     draw((0,y)--(11,y), linetype("4 4")); } clip((0,0)--(0,11)--(11,11)--(11,5)--(4,1)--cycle);[/asy]

$\text{(A)}\ \frac{1}{3} \qquad \text{(B)}\ \frac{4}{9} \qquad \text{(C)}\ \frac{1}{2} \qquad \text{(D)}\ \frac{5}{9} \qquad \text{(E)}\ \frac{5}{8}$

Solution

Problem 24

Miki has a dozen oranges of the same size and a dozen pears of the same size. Miki uses her juicer to extract 8 ounces of pear juice from 3 pears and 8 ounces of orange juice from 2 oranges. She makes a pear-orange juice blend from an equal number of pears and oranges. What percent of the blend is pear juice?

$\text{(A)}\ 30 \qquad \text{(B)}\ 40 \qquad \text{(C)}\ 50 \qquad \text{(D)}\ 60 \qquad \text{(E)}\ 70$

Solution

Problem 25

Loki, Moe, Nick and Ott are good friends. Ott had no money, but the others did. Moe gave Ott one-fifth of his money, Loki gave Ott one-fourth of his money and Nick gave Ott one-third of his money. Each gave Ott the same amount of money. What fractional part of the group's money does Ott now have?

$\text{(A)}\ \frac{1}{10} \qquad \text{(B)}\ \frac{1}{4} \qquad \text{(C)}\ \frac{1}{3} \qquad \text{(D)}\ \frac{2}{5} \qquad \text{(E)}\ \frac{1}{2}$

Solution

See Also

2002 AMC 8 (ProblemsAnswer KeyResources)
Preceded by
2001 AMC 8
Followed by
2003 AMC 8
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
All AJHSME/AMC 8 Problems and Solutions


The problems on this page are copyrighted by the Mathematical Association of America's American Mathematics Competitions. AMC logo.png