A swimming pool can be filled in 15 hours if water enters through a pipe alone or in 23 hours if water enters through a hose alone. if water is entering through both the pipe and the hose how long will it take to fill the pool 2/5 full?

In simplified form

Question

A swimming pool can be filled in 15 hours if water enters through a pipe alone or in 23 hours if water enters through a hose alone. if water is entering through both the pipe and the hose how long will it take to fill the pool 2/5 full?

In simplified form

anonymous · Answer

Is it multiple choice?

anonymous · Answer

no that's why I cannot figure it out ;(

ganeshie8 · Answer

Lets say the pool has a volume of "x" liters,
and it takes "t" hours to fill the poll if both pipe and hose are open.

ganeshie8 · Answer

$$\dfrac{x}{15}  + \dfrac{x}{23} = \dfrac{x}{t}$$

$$\implies   t =   \dfrac{15\times 23}{15+23}  = \dfrac{15\times 23}{38}$$

ganeshie8 · Answer

^^thats the time it takes to fill the pool `completely`

anonymous · Answer

I am still confused

ganeshie8 · Answer

since you want how much time it takes for filling 2/5th of the pool, just take 2/5 of above :


Time to fill 2/5th of pool =   $\dfrac{2}{5} \left(\dfrac{15 \times 23}{38}\right) = \dfrac{69}{19} $  hours