Question

A bag contains six identical black balls. A child withdraws one ball from the bag without looking into it. What is the probability that he takes out:

1. a white ball?
2. a black ball?

Answer 1

There are six identical black balls.

∴ No. of possible outcomes = 6.

(i) A white ball

As there is no white ball in the bag.

∴ No. of favourable outcomes (of getting a white ball) = 0.

P(getting a white ball) = `"No. of favourable outcomes"/"No. of possible outcomes"` = `0/6 = 0` 

Hence, the probability of getting a white ball = 0.

(ii) There are 6 identical black balls.

∴ No. of favourable outcomes (of getting a black ball) = 6.

P(getting a black ball) = `"No. of favourable outcomes"/"No. of possible outcomes"` = `6/6 = 1`

Hence, the probability of getting a black ball = 1.