Avem 2 modele de robinete, bazinele fiind aceleasi
r1 umple 3 bazine in 8h
r2 umple 1 bazin in 4
sau r1 umple intr-0 ora 3/8 bazin
r2 umple intr-o ora 1/4 bazin
Cele 2 robinete umplu intr-o ora 3/8+1/4=5/8 din bazin
avem ca r1 si r2..........1h.........5/8bazin
r1 si r2 xh 1 bazin
ri si r2 umplu in x ore un bazin x=1*1/[5/8}=8 ore/5=1h+3h/5=1h+60min/5=1h si 12 minute
