how do I set up this problem. John has bag of candy, gives 1/2 to his brother and 1/3 of remaining to his sister and has 15 left? how many did he start with?
starts with x
brother gets x/2, john still has x/2
sister gets 1/3 (x/2) = x/6
x - x/2 - x/6 = x/3 = 15, so x=45
check:
x/2 = 45/2
45/2/3 = 45/6
45 - 45/2 - 45/6 = 15
It works, but I didn't expect any fractions.