During a weight-lifting routine, an athlete calculates the total amount of weight moved while performing a certain exercise by multiplying the amount of weight per lift by the number of lifts. On Wednesday, the weight per lift was 20 percent greater than the weight per lift on Monday, while the number of lifts was 25 percent less than the number of lifts performed on Monday. On Friday, the weight per lift was 25 percent greater than the weight per lift on Wednesday, while the number of lifts was 40 percent less than the number of lifts performed on Wednesday. The total weight moved by the athlete while performing the exercise on Monday was approximately what percent greater than the total weight she moved while performing the exercise on Friday?
w be weight per lift.
W be total lift.
n be the number of lifts.
W=w×n
wwed=1.2wmon
nwed=0.75nmon
wfri=1.25wwed
wfri=1.25×1.2wmon=1.5wmon
nfri=0.6nwed
nfri=0.6×0.75nmon=0.45nmon
Wfri=nfri×wfri=0.45×1.5wmon=0.675wmon
wmon=1.48wfri
Monday she moved weight 0.48 more
⇒wmon−wfriwfri×100=487