Question

A cooler contains 12 bottles of apple juice and 18 bottles of orange juice. You reach into the cooler without looking and pull out one bottle of apple juice. Then you reach into cooler and pull out another bottle of juice. What is the probability of pulling apple juice and then pulling another apple juice?

Answer 1

P = 0.232

Explanation:

In the cooler, we have 12 bottles of apple juice and 18 bottles of orange juice.

This adds up to a total of 30 bottles.

Now we want to find the probability of pulling a bottle of apple juice after you pulled one bottle of apple juice.

The probability of pulling a bottle of apple juice at the beginning is equal to the quotient between the number of apple juice bottles in the cooler and the total number of bottles in the cooler,

This means that 12 out of 30 are apple juice, then the probability of getting first a bottle of apple juice is:

p = 12/30

Now, we want to find the probability of getting another, we will do the same calculation than above, but now the number of bottles of apple juice is 11 (because we took one) and the total number of bottles is 29.

In this case, the probability is:

q = 11/29

The joint probability (the probability of both events happening) is equal to the product of the individual probabilities.

Then the probability of pulling apple juice and then pulling another apple juice is:

P = p*q = (12/30)*(11/29) = 0.232