Question

A tank has a leak that can empty it in 4 hours. A pipe that admits 20 liters of water per hour into the tank is turned on and now the tank is emptied in 5 hours. What is the capacity of the tank in liters

Answer 1

Solution:

Part of the tank emptied by the leak in 1 hr = 1/4

Let part of the tank filled by the pipe in 1 hr = x

together in 1 hour = 1/5
so
1/4 - x = 1/5
x = 1/20

Part of the tank filled by the pipe in 1 hr = 1/20
so Tank can be filled  by the pipe in 20 hours

Capacity of the tank = 20 × 20 = 400 litres

Hope that helps!!!!