Question

two pumps are used to fill a water storage tank at a resort . one tank pump by itself in 9 hours and other can fill it in 6 hours . how long both pump operating together to fill the tank?

Answer 1

Solution: Let x=total time taken by both the pumps.

Both pumps would work at a rate of 1/x and individually, it would take 1/9 tank per hour and 1/6 tank per hour respectively.

Thus, together they can fill 1/9+1/6 tanks per hour. On solving, we get the value of x as 3 hour and 35 minutes.