Question

One pipe can fill a tank three times as fast as another pipe. If together the two pipes can fill the tank in$\text{36 minutes}$, then the slower pipe alone will be able to fill the tank in how many minutes.

Answer 1

Let the time required by a slower pipe alone to fill the tank be$\text{x minutes}$

Amount of tank filled in$\text{1 min =}\frac{1}{x}$

Let the time required by a faster pipe to fill the tank be $\frac{\text{x}}{3}\text{minutes}$

Amount of tank filled in$\text{1 min =}\frac{3}{x}$

Both pipes together fill the tank in$\text{36 minutes}$

Amount of tank filled by both pipes together in$\text{1 min =}\frac{1}{36}$

Therefore, $\frac{1}{x}+\frac{3}{x}=\frac{1}{36}$

$\frac{4}{x}=\frac{1}{36}$

$\text{x = 36×4 = 144 minutes}$

Hence, the time taken by slower pipe to fill the tank is$\text{144 minutes}$.