# Pipe and Cistern Questions for Railway Group D

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Download Pipes and Cisterns Questions & Answers PDF for RRB Group d exam. RRB Group d Questions based on asked questions on pipes and cisterns from previous exam papers, very important for the Railway Group d exam.

Question 1: Pipe A can fill a tank in 2 hrs and pipe B can empty the tank in 2.5 hrs, then find the time in which the tank would be filled if both pipes are opened at the same time ?

a) 10 hrs

b) 12 hrs

c) 8 hrs

d) 6 hrs

Question 2: Two pipes P and Q can empty a tank in 15 minutes and 30 mins respectively, then find the time taken to empty half the tank if both are opened at the same time ?

a) 10 min

b) 8 min

c) 6 min

d) 5 min

Question 3: Two pipes A and B can fill a tank in 4 hrs and 8 hrs respectively. Both the pipes are opened simultaneously, find the time needed to fill the tank?

a) $3\frac{1}{3}$ hrs

b) $3\frac{2}{3}$ hrs

c) $2\frac{2}{3}$ hrs

d) $2\frac{1}{3}$ hrs

Question 4: Pipe A can fill a tank in 2 hrs, Pipe B can fill the same tank in 3 hrs, In how many hours both pipes together can fill the tank ?

a) $1\frac{2}{5}$

b) $1\frac{1}{5}$

c) $1\frac{3}{5}$

d) $1\frac{4}{5}$

Question 5: Pipe A can fill a tank in 4 hrs whereas pipe B can empty the tank in 10 hrs, Find the total time in which tank will be filled if both pipes are opened ?

a) 5hrs 45mins

b) 5hrs 40mins

c) 6hrs 45mins

d) 6hrs 40mins

Question 6: Two taps A and B can fill a bucket in 12 hours and 15 hours respectively. If both are opened and A is closed after 3 hours, how much more time would it take for B to fill the bucket?

a) 7 hrs 15 min

b) 8 hrs

c) 8 hrs 30 mins

d) 8 hrs 15 mins

Question 7: In which of the following body parts digestion will not take place?

a) Mouth

b) Small intenstine

c) Stomach

d) Food pipe

Question 8: Why is lead pipe not used for drinking water?

a) It forms poisonous Lead Hydroxide

b) It forms poisonous Lead Carbide

c) It forms poisonous Lead Nitride

d) It forms poisonous Lead Monoxide

Question 9: What is the opening of the wind pipe called?

a) Larynx

b) Papillae

c) Glottis

d) Frenulum

Question 10: Find the efficiency of a pipe if it can fill a tank of volume 30000 litres in 2 minutes.

a) 15000 $m^3/sec$

b) 0.25 $m^3/sec$

c) 15 $m^3/sec$

d) 250 $m^3/sec$

Let the capacity of tank = LCM of 2 and 2.5 = 10 units

Filling efficiency of pipe A = 10/2 = 5 units/hr

Emptying efficiency of pipe B = 10/2.5 = 4 units/hr

If both pipes are opened,

The tank will be filled in 10/(5-4) = 10/(1) = 10 hrs

So the answer is option A.

Let the capacity of tank = LCM of 15 & 30 = 30 units

Efficiency of pipe P = 30/15 = 2 units/min

Efficiency of Pipe Q = 30/30 = 1 unit/min

Both pipes together can empty the half of the tank in 15/(2+1) = 15/3 = 5 mins

So the answer is option D.

Let Total capacity of tank = LCM of 4 and 8 = 8

Efficiency of A = 8/4 = 2

Efficiency of B = 8/8 = 1

Tank can be filled by both pipes in 8/(2+1) hrs = 8/3 hrs = $2\frac{2}{3}$ hrs

So the answer is option C.

Let the capacity of tank = LCM of 2&3 = 6 units

Efficiency of pipe A = 6/2 = 3

Efficiency of pipe B = 6/3 = 2

Both together can fill the tank in $\frac{6}{2+3} hrs = \frac{6}{5} hrs = 1\frac{1}{5}hrs$

So the answer is option B.

Let the capacity of tank = LCM of 4 & 10 = 20 units

Efficiency of A = 20/4 = 5 units/hr

Efficiency of B = 20/10 = 2 units/hr

Effective work = 5 – 2 = 3 units/hr

So tank will be filled in $20/3 = 6\frac{2}{3}hrs = 6 hrs 40 mins$

So the answer is option D.

Let the capacity of tank = LCM of 12 and 15 = 60 units

Efficiency of tap A = 60/12 = 5 units/hr

Efficiency of tap B = 60/15 = 4 units/hr

If both the taps are opened for 3 hrs, part of the tank that would be filled = (5+4)*3 = 27 units

Remaining part = 60 – 27 = 33 units

Tap B alone can fill 33 units of tank in 33/4 = $8\frac{1}{4} hrs = 8 hrs 15 mins$

So the answer is option D.

30000 litres = 30 $m^3$
=> efficiency = 30 $m^3$/120 seconds = 0.25 $m^3/sec$