Question

A pipe of 2 inch diameter fills the water tank in one hour. if the diameter of the pipe is 4 inch in what time will the pipe fill the same tank?

Answer 1

Time taken by pipe of diameter 2 inch = 1 hour
So
Time taken by pipe of diameter 1 inch will be equal to = 1/2 hour

Then
Time taken by pipe of diameter 4 inch is = 1/2*4
= 2 hour

Answer 2

Answer:

15 min because diameter increase time decrease