Question

2) 6 pipes are required to fill a tank in 1hour 20 min . How long will it take if only 5 pipes of the same type are used ?

Answer 1

6 pipes => 1 hr 20 mins
6pipes=>80mins
5pipes=>x mins
Therfore Total work done must be equal
=> 6*80 = 5 * x
=> x= 480/5
=> 96 mins
=> 1hr 36 mins