Three taps A, B and C can fill a tank in 12, 15 and 20 hours respectively. If A is open all the time and B and C are open for one hour each alternately, the tank will be full in_________?
A. 6 hours
B. 6 2/3 hours
C. 7 hours
D. 7 1/2 hours
A. 6 hours
B. 6 2/3 hours
C. 7 hours
D. 7 1/2 hours
A. 3 hrs 15 min
B. 3 hrs 45 min
C. 4 hrs
D. 4 hrs 15 min
A. 15 min
B. 20 min
C. 27.5 min
D. 30 min
A. 81 min.
B. 108 min.
C. 144 min.
D. 192 min.
A. 16 hrs
B. 20 hrs
C. 25 hrs
D. 40 hrs
Work done by leak in 1 hour = (1/8 – 1/10) = 1/40
The leak will empty the cistern in 40 hours.
A. 5 Hours
B. 6 Hours
C. 7 Hours
D. 8 Hours
Explanation:
Net filling in 1 hour = (1/2 – 1/3) = 1/6
Time taken to fill the cistern = 6 hours
A. 8
B. 10
C. 16
D. 24
Explanation:
Part filled by insert in 1 hour = 1/8
Part emptied by outlet in 1 hour = 1/16
Net filling in 1 hour = (1/8 – 1/16) = 1/16
Time taken to fill the tank = 1/16 hour= 16 hours
A. 10
B. 12
C. 14
D. 16
Explanation:
Part filled in 2 hours = 2/6 = 1/3.
Remaining part = 1 – 1/3 = 2/3
(A + B)’s 1 hour work = 2/21
C’s 1 hour work = [(A + B + C)’s 1 hour work – (A + B)’s 1 hour work]
= (1/6 – 2/21) = 1/14
C alone can fill the tank in 14 hours.
A. 5 min
B. 9 min
C. 10 min
D. 15 min
Explanation:
Let B be turned off after x minutes. Then, part filled by (A + B) in x min + part filled by A in (30 – x) min = 1.
x(2/75 + 1/45) + (30- x) 2/75 = 1
11x + 180 – 6x = 225 => x = 9
A. 60 gallons
B. 100 gallons
C. 120 gallons
D. 180 gallons
Explanation:
Work done by the waste pipe in 1 minute = 1/15 – (1/20 + 1/24) = – 1/40
Volume of 1/40 part = 3 gallons
Volume of whole = 3 * 40 = 120 gallons.