RRB Group-D Model Paper 20 with answers for online practice

The pump can fill the tank in 3 hours
∴ Part of the tank filled by the pump in 1 hour = 1/3
Let, the leak can drain all the water in ‘x’ hours
∴ Part of the tank leaked by the drain in 1 hour = 1/x
Given, Because of a leak, the pump took $3\frac{1}{5}$ hours= $\frac{16}{5}$ hours to fill the tank
1/3 - 1/x = 5/16
⇒ 1/x = 1/3 - 5/16
⇒ 1/x = (16 - 15)/46
⇒ 1/x = 1/48
⇒ x = 48 hours