Alex determines that there are 5 chocolate candies per cubic inch. if there are 150 chocolate candies in a jar, what is the volume of the jar?

The answer is 30 cubic inches.

If 5 chocolate candies are in 1 cubic inch, 150 chocolate candies will be in x cubic inches:
5 chocolate candies : 1 cubic inch = 150 chocolate candies : x cubic inches
5 : 1 = 150 : x
5 = 150 : x
x = 150 : 5
x = 30

So, if 150 chocolate candies are in a jar, the volume of the jar is 30 cubic inches.