SOLUTION: A pump can empty a tank 4 times as fast as the other. If both pumps are working, they can complete the job in 3 hours. Find the rate of each pump.

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Question 252632: A pump can empty a tank 4 times as fast as the other. If both pumps are working, they can complete the job in 3 hours. Find the rate of each pump.
Found 2 solutions by ankor@dixie-net.com, drk:
Answer by ankor@dixie-net.com(22740) (Show Source):
You can put this solution on YOUR website!
A pump can empty a tank 4 times as fast as the other.
If both pumps are working, they can complete the job in 3 hours.
Find the rate of each pump.
:
Let t = time required by the fast pump alone
then
4t = time required by the slow pump
:
Let the completed job = 1
:
+ = 1
Multiply by 4t, results
4(3) + 3 = 4t
12 + 3 = 4t
4t = 15 hrs, the time of the slow pump
and
t =
t = 3.75 hrs, the time of the fast pump
:
:
Check solution
3/3.75 + 3/15 =
.8 + .2 = 1

Answer by drk(1908) (Show Source):
You can put this solution on YOUR website!
This a job / time problem. Here is the formula
J1 / T1 * (together time) + J2 / T2 * (together time) = Total jobs.
Pump 2 does 1 job in x hours. So, J2 / T2 = 1/x.
Pump 1 does 1 job in 4x hours. So, J1 / T1 = 1/4x.
together time = 3
total jobs = 1 [1 tank].

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step 1 multiply by 4x.

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step 2 - solve for x.

15 = 4X
X = 15/4 = 3.75 hours.
Pump 2 rate = 4/15 hours
pump 1 rate = 1/15 hours.