Maria gave one half of her jelly beans to carol. carol gave one third of those to austin. austin gave one fourth of those to tony. if tony received two jelly beans, how many did maria start with?

48 is the answer. You multiply 2 by 4, that number 3 then that number by 2.

The easiest way to do this is to work backwards, starting by multiplying the amount that tony has by the  the bottom number of the fraction so that you know how much the previous person had. Also, if you like cross pultiplying fractions, that would work, too.   :) S...

2 x 4 = 8 (the amount that Austin has)
8 x 3 = 24 (the amount that Carol has)
24 x 2 = 48 (The amount that Maria has, aka the answer)