Problema Solution
A swimming pool holds 540,000 liters of water. The pool has two drainage pipes. When the pool is completely full, the first pipe alone can empty it in 120 minutes, and the second pipe alone can empty it in 180 minutes. When both pipes are draining together, how long does it take them to empty the pool?
Answer provided by our tutors
Pipe A finishes the job in 2 hours, which is the same as 120 minutes
Pipe B finishes the job in 3 hours, which is the same as 180 minutes
Therefore, Pipe A completes 1/2 of the job in one hour
and Pipe B finishes 1/3 of the job in one hour
Combined, they finish 1/3 + 1/2 of the job in one hour
when you add 1/3 and 1/2, you have 2/6 + 3/6, which equals 5/6
use the equation 5/6x = 1, where x is the number of hours needed to complete the full job (1 reperesents the full job)
5/6x = 1
divide both sides by 5/6
x = 1 / (5/6), when dividing fractions, multipy by the reciporical (flipped fraction)
x = 1 * 6/5
x = 6/5 = 1 and 1/5 hours
so the job will be completed in 1 and 1/5 hours, which is the same as 1.2 hours, which is the same as 1 hour and 12 minutes.
***if you need further explanation or have any questions feel free to message me! :)