Question

left on together the cold and hot water faucets of a certain bathtub Take 5 minutes to fill the tub if it takes the hot water faucet 15 minutes to fill the tub by itself how long will it take the cold water faucet to fill the tub on his own

Answer 1

So this a filling time question

So we will use the simple mathematical equation

Let hot water takes t1 and cold water takes t2 time respectively

So t1= 15 min

t2= x min (let)

And let together they fill in 5 mins.

`(1)/(t1)+(1)/(t2)=(1)/(t)`

So by using above equation we can calculate this.

`\begin{gathered} (1)/(15)+(1)/(x)=(1)/(5) \\ (1)/(x)=(1)/(5)-(1)/(15) \end{gathered}`

Therefore x comes out to be 15/2 mins. i.e. 7.5 mins

So Cold water takes 7.5 mins to fill.