Difference between revisions of "1986 AHSME Problems"
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+ | {{AHSME Problems | ||
+ | |year = 1986 | ||
+ | }} | ||
== Problem 1 == | == Problem 1 == | ||
− | <math>[x-(y- | + | <math>[x-(y-z)] - [(x-y) - z] =</math> |
<math>\textbf{(A)}\ 2y \qquad | <math>\textbf{(A)}\ 2y \qquad | ||
− | \textbf{(B)}\ | + | \textbf{(B)}\ 2z \qquad |
\textbf{(C)}\ -2y \qquad | \textbf{(C)}\ -2y \qquad | ||
− | \textbf{(D)}\ - | + | \textbf{(D)}\ -2z \qquad |
\textbf{(E)}\ 0 </math> | \textbf{(E)}\ 0 </math> | ||
Line 24: | Line 27: | ||
== Problem 3 == | == Problem 3 == | ||
− | <math>\triangle ABC</math> | + | <math>\triangle ABC</math> has a right angle at <math>C</math> and <math>\angle A = 20^\circ</math>. If <math>BD</math> (<math>D</math> in <math>\overline{AC}</math>) is the bisector of <math>\angle ABC</math>, then <math>\angle BDC =</math> |
<math>\textbf{(A)}\ 40^\circ \qquad | <math>\textbf{(A)}\ 40^\circ \qquad | ||
Line 63: | Line 66: | ||
== Problem 6 == | == Problem 6 == | ||
− | + | Using a table of a certain height, two identical blocks of wood are placed as shown in Figure 1. Length <math>r</math> is found to be <math>32</math> inches. After rearranging the blocks as in Figure 2, length <math>s</math> is found to be <math>28</math> inches. How high is the table? | |
− | < | + | <asy> |
− | + | size(300); | |
+ | defaultpen(linewidth(0.8)+fontsize(13pt)); | ||
+ | path table = origin--(1,0)--(1,6)--(6,6)--(6,0)--(7,0)--(7,7)--(0,7)--cycle; | ||
+ | path block = origin--(3,0)--(3,1.5)--(0,1.5)--cycle; | ||
+ | path rotblock = origin--(1.5,0)--(1.5,3)--(0,3)--cycle; | ||
+ | draw(table^^shift((14,0))*table); | ||
+ | filldraw(shift((7,0))*block^^shift((5.5,7))*rotblock^^shift((21,0))*rotblock^^shift((18,7))*block,gray); | ||
+ | draw((7.25,1.75)--(8.5,3.5)--(8.5,8)--(7.25,9.75),Arrows(size=5)); | ||
+ | draw((21.25,3.25)--(22,3.5)--(22,8)--(21.25,8.25),Arrows(size=5)); | ||
+ | unfill((8,5)--(8,6.5)--(9,6.5)--(9,5)--cycle); | ||
+ | unfill((21.5,5)--(21.5,6.5)--(23,6.5)--(23,5)--cycle); | ||
+ | label("$r$",(8.5,5.75)); | ||
+ | label("$s$",(22,5.75)); | ||
+ | </asy> | ||
− | <math>\textbf{(A)}\ | + | <math>\textbf{(A) }28\text{ inches}\qquad\textbf{(B) }29\text{ inches}\qquad\textbf{(C) }30\text{ inches}\qquad\textbf{(D) }31\text{ inches}\qquad\textbf{(E) }32\text{ inches}</math> |
− | \textbf{(B)}\ | ||
− | \textbf{(C)}\ | ||
− | \textbf{(D)}\ | ||
− | \textbf{(E)}\ | ||
[[1986 AHSME Problems/Problem 6|Solution]] | [[1986 AHSME Problems/Problem 6|Solution]] | ||
Line 90: | Line 102: | ||
== Problem 8 == | == Problem 8 == | ||
− | The population of the United States in <math>1980</math> was <math>226,504,825</math>. The area of the country is <math>3,615,122</math> square miles. | + | The population of the United States in <math>1980</math> was <math>226,504,825</math>. The area of the country is <math>3,615,122</math> square miles. There are <math>(5280)^{2}</math> |
square feet in one square mile. Which number below best approximates the average number of square feet per person? | square feet in one square mile. Which number below best approximates the average number of square feet per person? | ||
Line 115: | Line 127: | ||
== Problem 10 == | == Problem 10 == | ||
− | The <math>120</math> permutations of | + | The <math>120</math> permutations of <math>AHSME</math> are arranged in dictionary order as if each were an ordinary five-letter word. |
− | The last letter of the <math> | + | The last letter of the <math>86</math>th word in this list is: |
<math>\textbf{(A)}\ \text{A} \qquad | <math>\textbf{(A)}\ \text{A} \qquad | ||
Line 153: | Line 165: | ||
John scores <math>93</math> on this year's AHSME. Had the old scoring system still been in effect, he would score only <math>84</math> for the same answers. | John scores <math>93</math> on this year's AHSME. Had the old scoring system still been in effect, he would score only <math>84</math> for the same answers. | ||
− | How many questions does he leave unanswered? (In the new scoring system one | + | How many questions does he leave unanswered? (In the new scoring system that year, one received <math>5</math> points for each correct answer, |
− | <math>0</math> points for wrong | + | <math>0</math> points for each wrong answer, and <math>2</math> points for each problem left unanswered. In the previous scoring system, |
one started with <math>30</math> points, received <math>4</math> more for each correct answer, | one started with <math>30</math> points, received <math>4</math> more for each correct answer, | ||
− | lost | + | lost <math>1</math> point for each wrong answer, and neither gained nor lost points for unanswered questions.) |
− | |||
<math>\textbf{(A)}\ 6\qquad | <math>\textbf{(A)}\ 6\qquad | ||
Line 182: | Line 193: | ||
Suppose hops, skips and jumps are specific units of length. If <math>b</math> hops equals <math>c</math> skips, <math>d</math> jumps equals <math>e</math> hops, | Suppose hops, skips and jumps are specific units of length. If <math>b</math> hops equals <math>c</math> skips, <math>d</math> jumps equals <math>e</math> hops, | ||
− | and <math>f</math> | + | and <math>f</math> jumps equals <math>g</math> meters, then one meter equals how many skips? |
<math>\textbf{(A)}\ \frac{bdg}{cef}\qquad | <math>\textbf{(A)}\ \frac{bdg}{cef}\qquad | ||
Line 194: | Line 205: | ||
== Problem 15 == | == Problem 15 == | ||
− | A student attempted to compute the average <math>A</math> of <math>x, y</math> and <math>z</math> by computing the average of <math>x</math> and <math>y</math>, | + | A student attempted to compute the average, <math>A</math>, of <math>x, y</math> and <math>z</math> by computing the average of <math>x</math> and <math>y</math>, and then computing the average of the result and <math>z</math>. Whenever <math>x < y < z</math>, the student's final result is |
− | and then computing the average of the result and <math>z</math>. Whenever <math>x < y < z</math>, the student's final result is | ||
<math>\textbf{(A)}\ \text{correct}\quad | <math>\textbf{(A)}\ \text{correct}\quad | ||
Line 249: | Line 259: | ||
A plane intersects a right circular cylinder of radius <math>1</math> forming an ellipse. | A plane intersects a right circular cylinder of radius <math>1</math> forming an ellipse. | ||
− | If the major axis of the ellipse | + | If the major axis of the ellipse is <math>50\%</math> longer than the minor axis, the length of the major axis is |
<math>\textbf{(A)}\ 1\qquad | <math>\textbf{(A)}\ 1\qquad | ||
Line 329: | Line 339: | ||
== Problem 23 == | == Problem 23 == | ||
− | Let | + | Let <math>N = 69^{5} + 5 \cdot 69^{4} + 10 \cdot 69^{3} + 10 \cdot 69^{2} + 5 \cdot 69 + 1</math>. How many positive integers are factors of <math>N</math>? |
<math>\textbf{(A)}\ 3\qquad | <math>\textbf{(A)}\ 3\qquad | ||
Line 464: | Line 474: | ||
== See also == | == See also == | ||
− | |||
− | |||
* [[AMC 12 Problems and Solutions]] | * [[AMC 12 Problems and Solutions]] | ||
* [[Mathematics competition resources]] | * [[Mathematics competition resources]] | ||
+ | |||
+ | {{AHSME box|year=1986|before=[[1985 AHSME]]|after=[[1987 AHSME]]}} | ||
+ | |||
{{MAA Notice}} | {{MAA Notice}} |
Latest revision as of 17:30, 12 October 2023
1986 AHSME (Answer Key) Printable versions: • AoPS Resources • PDF | ||
Instructions
| ||
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 • 26 • 27 • 28 • 29 • 30 |
Contents
- 1 Problem 1
- 2 Problem 2
- 3 Problem 3
- 4 Problem 4
- 5 Problem 5
- 6 Problem 6
- 7 Problem 7
- 8 Problem 8
- 9 Problem 9
- 10 Problem 10
- 11 Problem 11
- 12 Problem 12
- 13 Problem 13
- 14 Problem 14
- 15 Problem 15
- 16 Problem 16
- 17 Problem 17
- 18 Problem 18
- 19 Problem 19
- 20 Problem 20
- 21 Problem 21
- 22 Problem 22
- 23 Problem 23
- 24 Problem 24
- 25 Problem 25
- 26 Problem 26
- 27 Problem 27
- 28 Problem 28
- 29 Problem 29
- 30 Problem 30
- 31 See also
Problem 1
Problem 2
If the line in the -plane has half the slope and twice the -intercept of the line , then an equation for is:
Problem 3
has a right angle at and . If ( in ) is the bisector of , then
Problem 4
Let S be the statement "If the sum of the digits of the whole number is divisible by , then is divisible by ."
A value of which shows to be false is
Problem 5
Simplify
Problem 6
Using a table of a certain height, two identical blocks of wood are placed as shown in Figure 1. Length is found to be inches. After rearranging the blocks as in Figure 2, length is found to be inches. How high is the table?
Problem 7
The sum of the greatest integer less than or equal to and the least integer greater than or equal to is . The solution set for is
Problem 8
The population of the United States in was . The area of the country is square miles. There are square feet in one square mile. Which number below best approximates the average number of square feet per person?
Problem 9
The product equals
Problem 10
The permutations of are arranged in dictionary order as if each were an ordinary five-letter word. The last letter of the th word in this list is:
Problem 11
In and . Also, is the midpoint of side and is the foot of the altitude from to . The length of is
Problem 12
John scores on this year's AHSME. Had the old scoring system still been in effect, he would score only for the same answers. How many questions does he leave unanswered? (In the new scoring system that year, one received points for each correct answer, points for each wrong answer, and points for each problem left unanswered. In the previous scoring system, one started with points, received more for each correct answer, lost point for each wrong answer, and neither gained nor lost points for unanswered questions.)
Problem 13
A parabola has vertex . If is on the parabola, then equals
Problem 14
Suppose hops, skips and jumps are specific units of length. If hops equals skips, jumps equals hops, and jumps equals meters, then one meter equals how many skips?
Problem 15
A student attempted to compute the average, , of and by computing the average of and , and then computing the average of the result and . Whenever , the student's final result is
Problem 16
In and side is extended, as shown in the figure, to a point so that is similar to . The length of is
Problem 17
A drawer in a darkened room contains red socks, green socks, blue socks and black socks. A youngster selects socks one at a time from the drawer but is unable to see the color of the socks drawn. What is the smallest number of socks that must be selected to guarantee that the selection contains at least pairs? (A pair of socks is two socks of the same color. No sock may be counted in more than one pair.)
Problem 18
A plane intersects a right circular cylinder of radius forming an ellipse. If the major axis of the ellipse is longer than the minor axis, the length of the major axis is
Problem 19
A park is in the shape of a regular hexagon km on a side. Starting at a corner, Alice walks along the perimeter of the park for a distance of km. How many kilometers is she from her starting point?
Problem 20
Suppose and are inversely proportional and positive. If increases by , then decreases by
Problem 21
In the configuration below, is measured in radians, is the center of the circle, and are line segments and is tangent to the circle at .
A necessary and sufficient condition for the equality of the two shaded areas, given , is
Problem 22
Six distinct integers are picked at random from . What is the probability that, among those selected, the second smallest is ?
Problem 23
Let . How many positive integers are factors of ?
Problem 24
Let , where and are integers. If is a factor of both and , what is ?
Problem 25
If is the greatest integer less than or equal to , then
Problem 26
It is desired to construct a right triangle in the coordinate plane so that its legs are parallel to the and axes and so that the medians to the midpoints of the legs lie on the lines and . The number of different constants for which such a triangle exists is
Problem 27
In the adjoining figure, is a diameter of the circle, is a chord parallel to , and intersects at , with . The ratio of the area of to that of is
Problem 28
is a regular pentagon. and are the perpendiculars dropped from onto extended and extended, respectively. Let be the center of the pentagon. If , then equals
Problem 29
Two of the altitudes of the scalene triangle have length and . If the length of the third altitude is also an integer, what is the biggest it can be?
Problem 30
The number of real solutions of the simultaneous equations is
See also
1986 AHSME (Problems • Answer Key • Resources) | ||
Preceded by 1985 AHSME |
Followed by 1987 AHSME | |
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 • 26 • 27 • 28 • 29 • 30 | ||
All AHSME Problems and Solutions |
The problems on this page are copyrighted by the Mathematical Association of America's American Mathematics Competitions.