It's 38.40 (:
How do you find out? well first you're going to want to multiply the percentage by the years so,
2 x 0.3 = 0.6
Then you're going to want to times the NEW percentage by the money made so,
640 x 0.6 = 3.84
All you want to do now is just move the decimal over one then add a zero
So, 38.40 is the answer! (:
