Question

A bag contains 4 white balls, 5 red balls and 8 black balls and 3 blue balls. A ball is drawn at random from the bag. Find the probability that the ball drawn is neither black nor red.

Answer 1

Given: A bag contains 4 white, 5 red, 8 black and 3 blue balls; one ball is drawn at random.

Step-wise calculation:

1. Total number of balls

= 4 + 5 + 8 + 3

= 20

2. Event "neither black nor red" = white or blue.

Number of favourable outcomes = 4 (white) + 3 (blue) = 7.

3. Probability = `"Number of favourable outcomes"/"Total number of outcomes"`

= `7/20`

4. As a decimal: `7/20 = 0.35`; as a percentage: 35%.

The probability that the ball drawn is neither black nor red is `7/20` (0.35 or 35%).