Question

$6$ pipes can fill a tank in $1$ hour $24$ minutes. How long will it take to full the tank if $7$ pipes are used

Answer 1

$1$ hour $=60$ minutes.

$1$ hour $24$ minutes $=60+24=84$ minutes

The time required to fill the tank by $6$ pipes $=84$ minutes

Time required to fill the tank by $1$ pipe $=84\times 6=504$ minutes.

Therefore,

Time required to fill the tank by $7$ pipes $=\frac{504}{7}=72$ minutes