Question

A bag contains 5 red , 8 black and 7 white balls. one ball is selected at random. what is the probability that the chosen ball is: 1)black 2)either red or white 3)neither black nor white.

Answer 1

1) probability = 8/20 = 2/5 = 0.4

2) probability = 12/20 = 3/5 = 0.6

3) probability = 5/20 = 1/4 = 0.25

Answer 2

p( e) = no. of favourable outcomes / total no. of sample space
1. 8/20 =2/5 ans
2. 12/20 =3/5
3. 5/20 = 1/4