Question

A ball is drawn at random from a box containing 12 white, 16 red and 20 green balls. Determine the probability that the ball drawn is not green. 

Answer 1

Total number of balls in the box = 48 

Total possible outcomes on drawing a ball = 48 

n(S) = 48   

Event of drawing a green ball = E = 2

n(E) = 20  

Probability of drawing a green ball = `(n(E))/(n(S)) = 20/48 = 5/12` 

Probability of not drawing a green ball = `1 - 5/12 = (12 - 5)/12 = 7/12`