Question

A bag contains 6 red, 5 black and 4 white balls. A ball is drawn from the bag at random. Find the probability that the ball drawn is not black.

Answer 1

Given: A bag contains 6 red, 5 black and 4 white balls; one ball is drawn at random.

Step-wise calculation:

1. Total number of balls

= 6 + 5 + 4

= 15

2. Number of balls that are not black

= red + white 

= 6 + 4

= 10

3. Probability (not black)

= `"Favourable"/"Total"` 

= `10/15`

= `2/3`

The probability that the ball drawn is not black is `2/3`.