Two pipes together can fill a tank in 6 hours. One pipe alone can do it in 12 hours. Another pipe alone can fill two tanks in -

Question: Two pipes together can fill a tank in 6 hours. One pipe alone can do it in 12 hours. Another pipe alone can fill two tanks in - Solution: let the second pipe fill the tank in X hours.in one hour both pipes can fill = 1/12 + 1/X= (X + 12)/12XAtq,12X/(X + 12) = 6x = 12 hours.to fill two tanks it will take = 24 hours