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Difference between revisions of "2003 AMC 12B Problems"

(Problem 18)
(Problem 19)
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== Problem 19 ==
 
== Problem 19 ==
 +
Let <math>S</math> be the [[set]] of [[permutation]]s of the [[sequence]] <math>1,2,3,4,5</math> for which the first term is not <math>1</math>. A permutation is chosen randomly from <math>S</math>. The [[probability]] that the second term is <math>2</math>, in lowest terms, is <math>a/b</math>. What is <math>a+b</math>?
 +
 +
<math>\mathrm{(A)}\ 5
 +
\qquad\mathrm{(B)}\ 6
 +
\qquad\mathrm{(C)}\ 11
 +
\qquad\mathrm{(D)}\ 16
 +
\qquad\mathrm{(E)}\ 19</math>
  
 
[[2003 AMC 12B Problems/Problem 19|Solution]]
 
[[2003 AMC 12B Problems/Problem 19|Solution]]

Revision as of 01:22, 19 July 2008

Problem 1

Which of the following is the same as

\[\frac{2-4+6-8+10-12+14}{3-6+9-12+15-18+21}\]?

$\text {(A) } -1 \qquad \text {(B) } -\frac{2}{3} \qquad \text {(C) } \frac{2}{3} \qquad \text {(D) } 1 \qquad \text {(E) } \frac{14}{3}$

Solution

Problem 2

Solution

Problem 3

Solution

Problem 4

Solution

Problem 5

Solution

Problem 6

Solution

Problem 7

Solution

Problem 8

Solution

Problem 9

Solution

Problem 10

Solution

Problem 11

Solution

Problem 12

Solution

Problem 13

Solution

Problem 14

Solution

Problem 15

Solution

Problem 16

Solution

Problem 17

Solution

Problem 18

Let $n$ be a 5-digit number, and let q and r be the quotient and remainder, respectively, when $n$ is divided by 100. For how many values of $n$ is $q + r$ divisible by 11?

$\text {(A) } 8180 \qquad \text {(B) } 8181 \qquad \text {(C) } 8182 \qquad \text {(D) } 9000 \qquad \text {(E) } 9090$

Solution

Problem 19

Let $S$ be the set of permutations of the sequence $1,2,3,4,5$ for which the first term is not $1$. A permutation is chosen randomly from $S$. The probability that the second term is $2$, in lowest terms, is $a/b$. What is $a+b$?

$\mathrm{(A)}\ 5 \qquad\mathrm{(B)}\ 6 \qquad\mathrm{(C)}\ 11 \qquad\mathrm{(D)}\ 16 \qquad\mathrm{(E)}\ 19$

Solution

Problem 20

Solution

Problem 21

Solution

Problem 22

Solution

Problem 23

Solution

Problem 24

Solution

Problem 25

Solution

See also