Question

7 pipes fill a tank in 50 minutes. How many minutes does it take if there are 11 pipes?

Give your answer to the nearest minute.

Answer 1

Answer: With 11 pipes, you need 31.82 minutes to fill the tank.

Explanation:

Let's define R as the rate at which one single pipe can fill a tank.

We know that 7 of them can fill a tank in 50 minutes, then we have the equation:

7*R*50min = 1 tank

Whit this equation, we can find the value of R:

R = 1 tank/(7*50min) = (1/350) tank/min.

Now that we know the value of R, we can do the same calculation but now with 11 pipes.

Then the time needed to fill the tank, T, is such that:

11*(1/350 tank/min)*T = 1 tank

We need to isolate T.

T = 1 tank/(11*(1/350 tank/min)) = 31.82 min

With 11 pipes, you need 31.82 minutes to fill the tank.