Pipe ‘A’ can fill a tank in 30 hours whereas leak

Solution

Let the capacity of the tank be 150 litres {LCM (30 and 50)} Efficiency of pipe ‘A’ = 150 ÷ 30 = 5 litres/hour Efficiency of leak ‘A’ = 150 ÷ 50 = 3 litres/hour Combined efficiency of pipe ‘A’ and leak ‘A’ = 5 – 3 = 2 litres/hour Combined efficiency of pipe ‘A’, ‘B’ and leak ‘A’ = 150 ÷ 15 = 10 units/hour Efficiency of pipe ‘B’ = 10 – 2 = 8 units/hour Time taken by pipe ‘B’ and leak ‘A’ to fill the tank = 150 ÷ (8 – 3) = 30 hours