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Problem 17

Combinatorics Difficulty 1.0 Find the answer CEMC Gauss (Grade 8) · Canada · 2011

A bag contains 15 balls. Exactly 3 of these balls are red. Alex reaches into the bag and randomly selects one of the balls. What is the probability that the ball that Alex selects is red?

(A) $\frac{1}{5}$ (B) $\frac{4}{5}$ (C) $\frac{1}{15}$ (D) $\frac{1}{4}$ (E) $\frac{14}{15}$

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