Question

Water tank can be filled in 7 hours by 5 equal sized pump working together how much time will seven pump take to fill

Answer 1

Step-by-step explanation:

5 pipes do in 7 hrs

1pipe does in 35 hrs

7 pipes do in 35/7 = 5hrs

or

time and men are inversely proportional

p¹/p² = t²/t¹

5/7 = t²/7

t²=5hrs

7 pipes does in 5hrs