RRB Paramedical Staff Nurse Model Paper 4

$1\mathit{h}=60$ min
Rate of emptying the tank by two taps are $\frac{1}{60}$ and $\frac{1}{30}$ of the tank per min. respectively.
Rate of emptying the tank when both operate simultaneously
$=\frac{1}{60}+\frac{1}{30}$
$=\frac{1+2}{60}$
$=\frac{3}{60}=\frac{1}{20}$ of the tank per minute