900/80=800/80+80/80+20/80=10+1+0.25=11.25940/60=600/60+300/60+40/60=10+5+2/3=47/3700/60=600/60+60/60+40/60=10+1+2/3=35/3870/40=800/40+80/40-10/40=20+2-0.25=21.75