2011-03-06, 08:54 PM
rate of fill for faucets = Vtub/15min
rate of fill for drain = -Vtub/20min
rate of fill with both = Vtub/15min + (-Vtub/20min) = Vtub/60min
Where Vtub is the volume of the tub.
So it would take 60min.
rate of fill for drain = -Vtub/20min
rate of fill with both = Vtub/15min + (-Vtub/20min) = Vtub/60min
Where Vtub is the volume of the tub.
So it would take 60min.