Question

A water pump takes 6 hours to fill an over head tank.standby pump takes 10 hours to fill the same tank .if the first pump fails after 2 hours then how long will the standby pump take to fill the rest

Answer 1

6.66h in hour frist pump fill 1/3part of the tank the 2/3part will remain which pump will fill in 20/3h. so second pump will fill the remain tank in 6.66 h

Answer 2

The pump takes 6 hours to fill the tank

⇒ 1 hour = 1/6 of the tank

Find the amount of water filled after 2 hours:

1 hour = 1/6 of the tank

2 hours = 1/6 x 2 = 1/3 of the tank

Find the amount of water to be filled:

Amount of water to be filled = 1 - 1/3 = 2/3 of the tank

Find the number of hours needed for the standby pump to fill the tank:

The standby pump takes 10 hours to fill the tank

1 tank = 10 hour

2/3 of the tank = 2/3 x 10 = 20/3 hours = 6 hours 40 mins

Answer: It will take 6 hours 40 mins for the standby pump to fill up the rest of the tank.