2005 AMC 12A Problems/Problem 23
Problem
Two distinct numbers a and b are chosen randomly from the set . What is the probability that is an integer?
Solution
Let , so . Define , ; then , so . Here we can just make a table and count the number of values of per value of . The largest possible value of is 12, and we get .
The total number of ways to pick two distinct numbers is , so we get a probability of .
See also
2005 AMC 12A (Problems • Answer Key • Resources) | |
Preceded by Problem 22 |
Followed by Problem 24 |
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All AMC 12 Problems and Solutions |
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