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Problem 33

Combinatorics Difficulty 1.0 Find the answer CEMC Gauss (Grade 7) · Canada · 2004

A box contains 1 grey ball, 2 white balls and 3 black balls. Without looking, John reaches in and chooses one ball at random. What is the probability that the ball is not grey?

(A) $1$ (B) $\dfrac{2}{6}$ (C) $\dfrac{3}{6}$ (D) $\dfrac{4}{6}$ (E) $\dfrac{5}{6}$

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