Difference between revisions of "2019 Mock AMC 10B Problems/Problem 6"
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<math>\textbf{(A)}\ \frac{1}{12}\qquad\textbf{(B)}\ \frac{1}{7}\qquad\textbf{(C)}\ \frac{1}{6}\qquad\textbf{(D)}\ \frac{1}{2}\qquad\textbf{(E)}\ \frac{2}{5}</math> | <math>\textbf{(A)}\ \frac{1}{12}\qquad\textbf{(B)}\ \frac{1}{7}\qquad\textbf{(C)}\ \frac{1}{6}\qquad\textbf{(D)}\ \frac{1}{2}\qquad\textbf{(E)}\ \frac{2}{5}</math> | ||
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Each die has <math>3</math> prime numbers: <math>2, 3, 5</math>. Since the numbers rolled on each die must be distinct, the answer is <math>\frac{3}{6} \cdot \frac{2}{6} = \boxed{\text{C} \frac{1}{6}}</math>. | Each die has <math>3</math> prime numbers: <math>2, 3, 5</math>. Since the numbers rolled on each die must be distinct, the answer is <math>\frac{3}{6} \cdot \frac{2}{6} = \boxed{\text{C} \frac{1}{6}}</math>. | ||
Revision as of 10:27, 3 November 2019
Problem
Mark rolled two standard dice. Given that he rolled two distinct values, find the probability that he rolled two primes.
Solution
Each die has 
prime numbers: 
. Since the numbers rolled on each die must be distinct, the answer is 
.
