A pipe can fill 1/8th of a tank in 1 hour. After filling 1/2 of the tank there was a resting period of 2 hours. The rest of the tank was filled simultaneously. What is the average time to fill the 1/8th of the tank?

Question: A pipe can fill 1/8th of a tank in 1 hour. After filling 1/2 of the tank there was a resting period of 2 hours. The rest of the tank was filled simultaneously. What is the average time to fill the 1/8th of the tank?

Solution:
to fill a full tank it will take 8 hours.
1/2 of the tank = 4 hours.
rest = 2 hours.
rest 1/2 of the tank = 4 hours.
total time = 10 hours.

1/10th of the tank will be filled in 1 hour.
1/8th of the tank in = 1.25 hours = 75 minutes