Answer:
Step-by-step explanation:
We have 3 identical pumps working to fill a pool. If it takes them working together 8 hours to fill the pool, the equation is:
[tex]\frac{1}{x}+\frac{1}{x}+\frac{1}{x}=\frac{1}{8}[/tex] and
[tex]\frac{3}{x}=\frac{1}{8}[/tex] . Cross multiply to get
x = 24, which is the number of hours it will take one pump to do the job all alone. If this be the case, and we have 4 pumps WORKING AT THE SAME TIME, filling the pool will be the number of hours it takes one pump divided by 4.
4 pumps can do the job in 6 hours.
