An ingoing pipe was used to fill a tank. But while using an outgoing pipe that can pour water in 10 hours at the same time, it took 8 hours to fill the tank. The ingoing pipe can fill the tank alone in -

Question: An ingoing pipe was used to fill a tank. But while using an outgoing pipe that can pour water in 10 hours at the same time, it took 8 hours to fill the tank. The ingoing pipe can fill the tank alone in -

Solution:
Let,
the ingoing pipe can fill the tank in X hours.
so, total fill-up in one hour = 1/X - 1/10
= (10 - X)/10X
ATQ,
10X/(10 - X) = 8
10X = 80 - 8X
18X = 80
X = 80/18 = 40/9 hours