Problema Solution
A pump can fill in a reservoir in 12 days. A second pump, operating independently can fill the same reservoir in 8 days. How long will it take to fill the reservoir if both pumps operate simultaneously.
Answer provided by our tutors
The first pump can fill in a reservoir in 12 days meaning in 1 day it will fill 1/12 of the reservoir.
The second pump can fill in a reservoir in 8 days meaning in 1 day it will fill 1/8 of the reservoir.
Let 'x' represent the number of days needed for the reservoir to fill when both pumps are working.
In 1 hour, both pumps will fill 1/x of the reservoir.
Now we can write the following equation:
1/12 + 1/8 = 1/x
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click here to see the equation solved for x
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x = 4.8 days
x = 4 days 24*0.8 hr
x = 4 days 19 hr 60*0.2 min
x = 4 days 19 hr 12 min
It will take 4 days 19 hr 12 min to fill the reservoir when both pumps operate simultaneously.