3/5 can be un-simplified into a number of different fractions. 3/5, 6/10, 12/20, etc.
The way we figure this out is by multiplying each side of the fraction by an integer. Say 2. So if the fraction is 3/4, times the top and bottom by 2 making it 6/8
Take 45.36 *.08 to get the price of the sweater 45.36 *.08 =3.6288 so take 45.36-3.63= 41.73 and take 41.73 *.25 = 10.4325 take 41.73+10.43=52.16 is the original price of the sweater