Question

Seven taps can fill a tank in 6 hours. How long will it take twelve taps of similar flow rate to fill the same tank?

Answer 1

Let us suppose 12 taps fills the tank in “x” hours
As the number of tank increases, the time to fill decreases.
So, the number of tanks and time to fill are in inverse proportion.
$\therefore 7\times 6=12\times x$
$\Rightarrow x=\frac{42}{12}$
$\Rightarrow x=3.5$
Hence, 12 taps will fill the tank in 3.5 hours or 3 hours 30 minutes.