Working alone, two pipes A and B require 9 hours and 6.25 hours more respectively to fill a pool than if they were working together. Find the total time taken to fill the pool if both were working together.
6
6.5
7
7.5
Explanation:
Let the time taken if both were working together be n hours.
=> Time taken by A = n + 9
=> Time taken by B = n + 6.25
In such kind of problems, we apply the formula : n2 = a x b,
where a and b are the extra time taken if both work
individually than if both work together.
Therefore, n2 = 9 x 6.25 => n = 3 x 2.5 = 7.5
Thus, working together, pipes A and B require 7.5 hours.
Let the time taken if both were working together be n hours.
=> Time taken by A = n + 9
=> Time taken by B = n + 6.25
In such kind of problems, we apply the formula : n2 = a x b,
where a and b are the extra time taken if both work
individually than if both work together.
Therefore, n2 = 9 x 6.25 => n = 3 x 2.5 = 7.5
Thus, working together, pipes A and B require 7.5 hours.