math working backwards
posted by luckybee on .
Sandra spent onefifth of her money and loaned onethird of the remainder to her brother. She had $24 left. How much did she begin with?

m  1/5 m = 4/5 m
4/5 m * 1/3 = 4/15 m
m  1/5 m  4/15 m = 24
m = 45 
When working backwards we first need to deal with 1/3. so since it says 1/3 of the remainder, does this mean to divide 24 by 1/3

if r is the remainder, then
24 = 2/3 r
r = 36
r = 4/5 m, so
m = 5/4 * 36 = 45 
I understand thank you.