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