3/4 part of the tank is full of water. When 30 liters of water is taken out, the tank becomes empty. The capacity of the tank is -

Question: 3/4 part of the tank is full of water. When 30 liters of water is taken out, the tank becomes empty. The capacity of the tank is -

Solution:
If the tank has 4x liters of total capacity and its holds 3x liters of water.
If 30 liters of water is taken out, then the tank becomes empty.

It means 3x liters of water is taken out
3x = 30 liters
x = 10 liters

Capacity of tank = 4x = 4 × 10 = 40 liters