Question 1101614
x=price last week, 27% less is 0.27.  Since it is 27% less than 100%, that is 100%-27%=73%, which is 0.73
0.73x=price now=$15
divide by 0.73 both sides
15/0.73=$20.55 price last week ANSWER

Check this 
% less is decrease /original amount
this is 5.55/20.55=0.27