Question

Chanelle selects a marble from a container and then returns it to the container. When she does this 3 times, the probability of choosing a red marble all 3 times is 1/216. Based on this information, what is the probability of Chanelle choosing a red marble the first time she selects a marble?

Answer 1

1 ÷ 6

Explanation:

Let us assume the probability of the red marble for selecting it first time be x

And, it is to be done 3 times

that means

= 1 ÷ x × 1 ÷ x × 1 ÷ x

This equivalent to = 1 ÷ 216

And the 216 could be calculated by multiplied 6 3 times i.e.

= 6 × 6 × 6

= 216

So, the probability for selecting it for a first time is

= 1 ÷ 6