Question

9 identical pipes take 70 minutes to fill a tank. If two of
the pipes don't work, then how much time would it take
remaining pipes to fill the tank?​

Answer 1

Answer:

the relation between no. of pipe and time taken is inverse relation. since two pipes are not working 7 pipes will have to do what 9 pipes did. So,

9 identical pipes take 70 minutes to fill a tank

1 pipe will take 70*9 minutes to fill the tank

7 pipes will take 70*9/7 minute to fill the tank

= 90 minutes