Question

A bag contains 3 red balls, 4 blue balls and 1 yellow ball, all the balls being identical in shape and size. If a ball is taken out of the bag without looking into it; find the probability that the ball is neither yellow nor red. 

Answer 1

Total number of balls in the bag = 3 + 4 + 1 = 8 

Number of possible outcomes = 8 = n(S) 

Neither yellow ball nor red ball means a blue ball 

Event of not drawing a yellow or red ball = E = 4 

n(E) = 4 

Probability of not drawing a yellow or red ball = `(n(E))/(n(S)) = 4/8 = 1/2`