6 Pipes

6 Pipes are required to fill a tank in 1 hour 20 minutes. How long will it take if only five pipes of the same type are used? Give your answer in hours and minutes.

Result

t₂ = 1:36 hh:mm

Step-by-step explanation:

$$\begin{gathered} n_1=6 \\ {t}_1=1:20=1hr20min=1+\frac{20}{60}=1.3333hr\doteq 1.3333 \\ {n}_2=5 \\ {V}_1=V_2 \\ {n}_1\cdot t_2=n_2\cdot t_2 \\ {t}_2=t_1\cdot \frac{n_1}{n_2}=\frac{4}{3}\cdot \frac{6}{5}=\frac{4\cdot 6}{3\cdot 5}=\frac{24}{15}=1.6=1:36\text{hh}:\text{mm} \end{gathered}$$

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