Question

8 pipes are required to fill a tank in 1 hr 20 min. How long will it take if only 6 pipes of the same type are used?

Answer 1

Let the required time be ‘t’ hours.

Number of pipe	8	6
Time (in hours)	$\frac{4}{3}$	t

$[\because 1\text{hr}20\text{min}=\frac{4}{3}h]$

$\text{Less number of pipes}\Rightarrow \text{more time}$

$\therefore x_1{y}_1=x_2{y}_2$

$\Rightarrow 8\times \frac{4}{3}=6\times t$

$\Rightarrow t=\frac{8\times 4}{6\times 3}=\frac{16}{9}h$

$=1\frac{7}{9}h.$

$\text{Hence, the required time}=1\frac{7}{9}h.$