Question

Working together, two pumps can drain a certain pool in

Answer 1

Answer:

10.5 hours.

Step-by-step explanation:

Given,

Two pumps can drain a certain pool in 6 hours.

So, the combined one hour work of the pumps = $\frac{1}{6}$,

Also,older pump  takes 14  hours to drain the pool by itself,

The one hour work of older pump = $\frac{1}{14}$,

Thus, the one hour work of newer pump = Combined one hour work - one hour work of older pump,

$=\frac{1}{6}-\frac{1}{14}$

$=\frac{7-3}{42}$

$=\frac{4}{42}$

Hence, the total time taken by newer pump = $\frac{1}{4/42}=\frac{42}{4}=10.5\text{ hours}$

Answer 2

New pump = (Old Pump * Total) / (Old Pump - Total)
New pump = (14 * 6) / (14 -6)
New pump = (84) / (8)
New Pump = 10.5 hours