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Water can be pumped from a
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10 Aug 2020, 10:13
10 Aug 2020, 10:13
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88% (02:10) correct
11% (02:38) wrong based on 54 sessions
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Water can be pumped from a 100,000 gallon tank at a uniform rate by opening valve V, valve W, or both. The rate at which water is pumped out by opening valve V is 10,000 gallons per hour. If the tank is completely full and both valves are opened, the tank can be drained in 6 hours. How long would it take to empty the tank if it were 80% full and only valve W were opened?
A. 6 hours
B. 8 hours
C. 12 hours
D. 15 hours
E. 18 hours
A. 6 hours
B. 8 hours
C. 12 hours
D. 15 hours
E. 18 hours
Re: Water can be pumped from a
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11 Aug 2020, 04:22
11 Aug 2020, 04:22
1
Rate :
v = 10,000 g/h
w = w
t = 6 h
100000 = 6 * 10,000 + 6 * w
w = 6666.666...
Now, 80% of 100,000 = 80,000
So,
80,000 = T * (6666.666)
T = 12h (approx.)
v = 10,000 g/h
w = w
t = 6 h
100000 = 6 * 10,000 + 6 * w
w = 6666.666...
Now, 80% of 100,000 = 80,000
So,
80,000 = T * (6666.666)
T = 12h (approx.)
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Re: Water can be pumped from a
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12 Aug 2020, 05:31
12 Aug 2020, 05:31
3
Carcass wrote:
Water can be pumped from a 100,000 gallon tank at a uniform rate by opening valve V, valve W, or both. The rate at which water is pumped out by opening valve V is 10,000 gallons per hour. If the tank is completely full and both valves are opened, the tank can be drained in 6 hours. How long would it take to empty the tank if it were 80% full and only valve W were opened?
A. 6 hours
B. 8 hours
C. 12 hours
D. 15 hours
E. 18 hours
A. 6 hours
B. 8 hours
C. 12 hours
D. 15 hours
E. 18 hours
If the tank is completely full and BOTH valves are opened, the tank can be drained in 6 hours.
Rate = output/time
So, the COMBINED rate of valves W and V = 100,000/6 gallons per hour
GIVEN: The rate at which water is pumped out by opening valve V is 10,000 gallons per hour.
So, the rate of valve W = 100,000/6 - 10,000
= 100,000/6 - 60,000/6
= 40,000/6 gallons per hour
How long would it take to empty the tank if it were 80% full and only valve W were opened?
80% of 100,000 gallons = 80,000 gallons.
time = output/rate
So, time = 80,000/(40,000/6)
= (80,000)(6/40,000)
= 12 hours
Answer: C
Cheers,
Brent
