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09 Oct 2020, 04:15
Kudos
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C
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
25%
(medium)
Question Stats:
83% (02:28) correct
17%
(03:02)
wrong
based on 263
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
09 Oct 2020, 04:29
Kudos
Bookmarks
Explanation:
Rate of V is 10000 gallons per hour
Valve V empty tank in = 100000/10000 = 10 hours.
Both valves empty tank in 6 hours
So Eqn will be :
1/w + 1/v = 1/b
1/w = 1/b - 1/v
1/w = 1/6 - 1/10
1/w = 4/60
w = 15 Hours.
So valve w alone will empty the tank in 15 hours.
So valve w alone empty 80% of tank = 0.8x15 = 12 Hours
IMO-C
Rate of V is 10000 gallons per hour
Valve V empty tank in = 100000/10000 = 10 hours.
Both valves empty tank in 6 hours
So Eqn will be :
1/w + 1/v = 1/b
1/w = 1/b - 1/v
1/w = 1/6 - 1/10
1/w = 4/60
w = 15 Hours.
So valve w alone will empty the tank in 15 hours.
So valve w alone empty 80% of tank = 0.8x15 = 12 Hours
IMO-C
09 Oct 2020, 08:39
Kudos
Bookmarks
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
Explanation:
Pump our rate for V=10000 gallon per hour
100000 gallon Tank water will be pumped out by V in=10000/10000 hrs=10 hrs
Let the time taken by W to pump out water of whole tank be W hrs
then as per given information,
1/V+1/W=1/6
1/10+1/W=1/6
W=15 hrs
i.e W takes 15 hrs to pump out 100000 gallon water
time taken by W to pump out 100000*0.8 gallon water= (15/100000)*100000*0.8
=12 hrs
Hence C is the correct answer.
A. 6 hours
B. 8 hours
C. 12 hours
D. 15 hours
E. 18 hours
Explanation:
Pump our rate for V=10000 gallon per hour
100000 gallon Tank water will be pumped out by V in=10000/10000 hrs=10 hrs
Let the time taken by W to pump out water of whole tank be W hrs
then as per given information,
1/V+1/W=1/6
1/10+1/W=1/6
W=15 hrs
i.e W takes 15 hrs to pump out 100000 gallon water
time taken by W to pump out 100000*0.8 gallon water= (15/100000)*100000*0.8
=12 hrs
Hence C is the correct answer.
