Question

The probability of selecting a blue marble at random from a jar that contains only blue,black and green marbles is 1/5. The probability of selecting a black marble at random from the same jar is 1/4. If the jar contains 11 green marbles, find the total number of marbles in the jar.

Answer 1

Answer:

The total number of marble in the jar is 20

Step-by-step explanation:

Given the probability of selecting blue marble = 1/5 = 0.2

the probability of selecting black marble = 1/4 = 0.25

Hence probability of selecting green marble = 1 - (0.2 + 0.25) = 0.55

Number of green marble = 11

Let the total number of marble = x

=> 11/x = 0.55

=> x = 11/0.55 = 20

Hence the total number of marble in the jar is 20