PIPES AND CISTERNS PRACTICE TEST I:
Q1. Two pipes A and B can fill a tank in 20 minutes and 30 minutes respectively. If both pipes are opened together, the time taken to fill the tank is:
a) 50 minutes b) 12 minutes c) 25 minutes d) 15 minutes
Q2. Three tapes A, B, 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 alternatively, the tank will be full in:
a) 6 hours b) 13/2 hours c) 7 hours d) 15/2 hours
Q3. A tap can empty a tank in one hour. A second tap can empty it in 30 minutes. If both the taps operate simultaneously, how much time is needed to empty the tank?
a) 20 minutes b) 30 minutes c) 40 minutes d) 45 minutes
Q4. A pump can fill a tank with water in 2 hours. Because of a leak in the tank it was taking 7/3 hours to fill the tank. Leak can drain all the water off the tank in:
a) 8 hours b) 7 hours c) 13/3/ hours d) 14 hours
Q5. A pipe can fill a tank with water in 3 hours. Due to leakage in bottom, it takes 7/2 hours to fill it. In what time the leak will empty the fully filled tank?
a) 12 hours b) 21 hours c) 13/2 hours d) 21/2 hours
Q6. Two pipes A and B can fill cistern in 75/2 minutes and 45 minutes respectively. Both pipes are opened. The cistern will be filled just in half an hour, if the pipe B is turned off after:
a) 15 minutes b) 10 minutes c) 5 minutes d) 9 minutes
Q7. Two pipes can fill a tank with water in 15 and 12 hours respectively, and a third pipe can empty it in 4 hours. If the pipes be opened in order, at 8, 9 and 11 a.m. respectively, the tank will be emptied at
a) 11:40 am b) 12:40 am c) 1: 40 pm d) 2: 40 pm
Q8. A tank can be filled with water by two pipes A and B together in 36 minutes. If the pipe B was stopped after 30 minutes, the tank is filled in 40 minutes. The pipe B can alone fill the tank in
a) 45 minutes b) 60 minutes c) 75 minutes d) 90 minutes
Q9. A tank has a leak which would empty the completely filled tank in 10 hours. If the tank is full of water and a tap is opened which admits 4 litres of water per minute in the tank, the leak takes 15 hours to empty the tank. How many litres of water does the tank hold?
a) 2400 b) 4500 c) 1200 d) 7200
Q10 Three pipes A, B, and C can fill a cistern in 6 hours. After working at it togther for 2 hours, C is closed and A and B fill it in 7 hours more. The time taken by C alone to fill the cistern is
a) 14 hours b) 15 hours c) 16 hours d) 17 hours
Q11. A pipe of diameter d can drain a cerian water tank in 40 minutes. The time taken by a pipe of diameter 2 d for doing the same job in:
a) 5 minutes b) 10 minutes c) 20 minutes d) 80 minutes
Q12. A swimming pool has 3 drain pipes. The first two pipes A and B, operating simultaneouly, can empty the pool in half the time C, the 3rd pipe, alone takes to empty it. Pipe A working alone, takes half the time taken by pipe B. Together they take 6 hours 40 minutes to empty the pool. Time taken by pipe A to empty the pool, in hours is
a) 20 b) 10 c) 30 d) 7
Answer key
1 b 2 c 3 a 4 d 5 b 6 d 7 d 8 d 9 d 10 a 11 b 12. a
For More Practice:
Practice Test I CLICK HERE!!
Practice Test II CLICK HERE!!
Basics of Pipes and Cisterns CLICK HERE!!
Sir please provide solution for 7,9,11and12questions
ReplyDeleteHello Abhi,
ReplyDeleteIn Question 7 the answer is 2:40 Pm i.e option D. Thanks for correcting us.
The Solution 7:
A can fill in 15 hr. starts at 8 am
B can fill in 12 hr. starts at 9 am.
C empty fill in 4 hr. starts at 11 am.
A and B can fill the Tank portion till 11 am.
3/15 +2/12 = 11/30
Now Pipe has been opened. Now portion of water can empty in 1 hr.
1/15 + 1/12 - 1/4 = -1/10.
Now tank will empty in.( x hr after 11 am)
11/30 - x/10 = 0.
Therefore, x = 11/3 = 3 hr 40 min.
Time = 11 + 3 hr 40 min = 2:40 PM
Regarding Question 9
Let the quantity of tank be "X lt".
Quantity of water ejected per minute due to leak = X/600.
Quantity of water added due to another tape= 4 lt/min.
The tank get emptied in 15 hr.
water added to tank is 4x60x15 + X (because the tank was already filled.)
Water ejected from tank in 15 hr = 1.5X lt.
Now tank is empty after 15 hr therefore there is no Water in tank,
Water Added in 15 hr - Water ejected in 15 hr. = 0.
4x60x15 + X - 1.5X = 0.
4x60x15 = 0.5X.
Therefore, X = 7200 lt. Which is our answer.
Regarding Question 11
ReplyDeleteThe discharge through a pipe is the volume discharged through.
In this question the length/height of pipe remains same,
Volume = pie*r^2*h...................1
We are given when the dia= d the time taken is 40 min,
And we need to find the time when dia = 2d,
Using 1.
the discharge from 2d will be 4 time .
thus time taken will be 1/4th time which is 40/4 min =10 min. which is our answer.
Regarding Question 12.
Solution. Taken taken to empty is 400 min,
Let time taken by A,B and C be "A" "B" and "C" min
As per statement 1/A + 1/B = 1/C...........1
And A=B/2 min................2
Using all,
1/A + 1/B + 1/C = 1/400
Taking this equation in terms of A we get,
3/A = 1/400.
A= 1200 min.
converting it in hr,
We get A = 20 hr. which is our answer.
Thanks .for providing answers to my problems
ReplyDelete