Question

A bag contains 3 white, 4 red and 5 black balls. One ball is drawn at random. What is the probability that the ball drawn is neither black nor white?
(a) $\frac{1}{4}$ (b) $\frac{1}{2}$ (c) $\frac{1}{3}$ (d) $\frac{3}{4}$

Answer 1

Given
total number of balls=3+4+5=12
Number of balls which are neither black nor white=4

hence the probabity that the ball drawn is neither white nor black=