Question

A jar contains 24 marbles. Some of these are green and others are blue. If a marble is drawn at random from the jar, the probability that it is green is ` 2/3`. Find the number of blue marbles in the jar.

Answer 1

Correct Answer - 8
Total number of marbles in the jar = 24.
Let the number of blue marbles be x.
Then,the numbers of green marbles = 24 - x.
P(getting a green marble) =` (24-x)/24` .
But, P(getting a green marble) = `2/3` (given).
` :. (24-x)/24 = 2/3 rArr 72 - 3x = 48 rArr 3x = 24 rArr x = 8`.
Hence, the number of blue marbles in the jar is 8.