Question

8 pumps can empty a water tank in 42 hours. How many hours will 56pumps take to do the same work

Answer 1

Pumps                                                                                             Time                                        

  8                                                                                                      42 h

  56                                                                                                   x

8 * 42 = 56 * x

( 8 * 42 ) / 56 = x

= 6 hours

56 pumps will take 6 hours to do the same work.

Answer 2

Answer:

Time taken by 56 such pumps to empty the tank = 6 hours

Step-by-step explanation:

Time taken by 8 pumps to empty a tank = 42 hours

We need to find time taken by 56 such pumps to empty the tank.

Let the time taken by 56 pumps to empty the tank be x

Pumps      Time Taken

8                    42

56                   x

As the number of pumps are increasing so the time taken will also decrease. Therefore, It is an inverse variation.

⇒ 56 × x = 8 × 42

⇒ 56·x = 336

⇒ x = 6

Therefore, Time taken by 56 such pumps to empty the tank = 6 hours