Question

15. A water pump takes 6 hours to fill an over head tank Standby pump takes 10 hours to till the same over head tank. If first pump fails after 2 hours of running, then how long will the standby pump take to fill the overhead tank?

Answer 1

7 hours 27 minutes is the right answer.....

                                 HOPE IT HELPS..........:-)

Answer 2

Water pump takes 6 hours

⇒ 1 hour = 1/6 of the tank

Find the amount of tank filled after 2 hours

1 hour = 1/6 of the tank

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

Amount of water left to fill:

Amount of water left to fill = 1 - 1/3 = 2/3 of the tank

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

The standby pump takes 10 hours

Full tank = 10 hours

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

Answer: It takes 6 hours and 40 mins to fill up the rest of the tank.