Question

Edna spent 4/13 of her weekly allowance on snacks, 2/7 of the remainder on books and 1/8 of what remained on transportation. If she still had $100, how much was her weekly allowance

Answer 1

total allowance ---- x
amount left after getting snacks = (9/13)(x) = 9x/13
amount left after buying books = (5/7)(9x/13) = 45x/91
amount left after transportation = (7/8)(45x/91) = 45x/104

then 45x/104 = 100
45x = 10400
x = 231.11

Her allowance was 231.11

check:
she spent 4/13 of 231.11 or 71.11 on snacks, leaving her with160
she spent 2/7 of 160 on books, or 45.714, leaving her with 114.2857
she spent 1/8 of 114.2857 on transp, or 14.2857, leaving her with 100.00

my answer is correct.