Question

A water tank had three inlets, wltich
independently can fill the tank in 20, 40
and 30 minutes, respectively. How much
time does it take to fill the tank when all
three inlets work together?​

Answer 1

It takes 13.33 minutes to fill the tank if all the 3 inlets are opened together.

Answer 2

Answer:

Since we have given that

Time taken by first water tank = 20 minutes

Time taken by second water tank = 40 minutes

Time taken by third water tank = 30 minutes

So, we need to find the time taken to fill the tank when all work together.

So, it becomes,

\begin{gathered}\dfrac{1}{20}+\dfrac{1}{40}+\dfrac{1}{30}\\\\=\dfrac{6+3+4}{120}\\\\=\dfrac{13}{120}\\\\\end{gathered}

20

1

+

40

1

+

30

1

=

120

6+3+4

=

120

13

So, It takes \dfrac{120}{13}

13

120

minutes to fill the tank when all work together.

# learn more:

A water tank has 3 inlets. Inlet A alone can fill the tank in 30 minutes. Inlet B can fill it in 40 minutes Inlet C can fill it in 60 minutes. If all the 3 inlets are opened together, how long will it take to fill the tank?