Question

A box contains 7 red balls, 8 green balls and 5 white balls. A ball is drawn at random from the box. Find the probability that the ball is white.

Answer 1

Total number of balls in the box = 7 + 8 + 5 = 20 balls 

Total possible outcomes = 20 = n(S) 

Event of drawing a white ball = E = number of white balls 

n(E) = 5

Probability of drawing a white ball= `(n(E))/(n(S)) = 5/20 = 1/4`