If the first pipe can fill the pool in 9 hours that means that in 1 hour it fills of the pool, we use the same logic for the second pipe and conclude that in 1 hour it feels up of the pool. If both were to fill the pool together that means that in 1 hour they would fill...
of the pool in 1 hour.
Now to find how many hours it will take divide the pool by the speed with which it is getting filled.
hours
3.6 hours in other words is 3 hours and 36 minutes.
If it took 4 miles per hour you multiply that twice cuss its traveling back then forth so you repeat the same process 30 miles times 2 which is 60 hope this helps.
