Quantitative Aptitude

Pipes and Cisterns

69 Questions

Pipes and cisterns problems test your understanding of inlet and outlet rates alongside time management. These questions are a staple in quantitative aptitude sections for SSC, banking, and railways. Mastering filling and emptying concepts is essential for scoring well.

inlet outlet pipestank filling timeleak and drainagemultiple pipe efficiencywork and time rates

Pipes and Cisterns Questions

Multiple choice botany caskets of life the cell structure multicellular organisms number and shape of cells

Bacterial cell divides every two minutes. It takes 20 minutes a cup to be one-fourth full. How much time it will take to fill the cup?

  1. 24 minute

  2. 60 minute

  3. 40 minute

  4. 50 minute
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

If the cup is one-fourth full at 20 minutes, it will be half full at 22 minutes (doubling every 2 minutes) and completely full at 24 minutes.

Multiple choice maths ratio, proportion and unitary method more on proportion terms related to proportion proportion

A leak in the bottom of a tank can empty the full tank in $6$ hours. An inlet pipe fills water at the rate of $4$ litres per minute. When the tank is full, the inlet is opened and due to the leak, the tank is empty in $8$ hours, then the capacity of the tank is:

  1. $5260$ L
  2. $5760$ L
  3. $5846$ L
  4. $6970$ L
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Work done by the inlet in 1 hour $= \dfrac{1}{6}.\dfrac{1}{4}=\dfrac{1}{24}$

Work done by inlet in 1 min $=\dfrac{1}{24}\times \dfrac{1}{60}$
                                           
                                              $=\dfrac{1}{1440}$

Volume of$ \dfrac{1}{1440}$ part$ = 4$ litres
Volume of whole = $(1440 \times 4)$litres=$5760$  litres

Multiple choice biology soil : our life soil properties soil - properties basics of soil pollution

The normal capacity of percolation tank is 

  1. 7.0 mm/day

  2. 7.87 mm/day

  3. 5.87 mm/day

  4. 0.87 mm/day
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Percolation tanks are the most prevalent structures as it is a measure to recharge the groundwater reservoir both in alluvial as well as hard rock formations.The size of percolation tank should be governed by percolation capacity of strata in the tank bed. Normally, the capacity of percolation tank is 7.87 mm/day.

So, the correct answer is option B.

Multiple choice maths fundamental concept of ratio and proportion division problem dividing a quantity in a given ratio problems on ratios

Four taps can individually fill a cistern of water in $1$ hour, $2$ hours, $3$ hours and $6$ hours respectively. If all the four taps are opened simultaneously, the cistern can be filled in how many minutes?

  1. $20$
  2. $30$
  3. $35$
  4. $40$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

$4$ taps individually fill a cistern of water in $1$ hour, $2$ hours, $3$ hours and $6$ hours.
Part of the cistern filled in one hour
$= \left (1 + \dfrac {1}{2} + \dfrac {1}{3} + \dfrac {1}{6}\right ) = 2$
$\Rightarrow$ Twice the capacity is full in $60$ min.
Therefore, cistern is full in $30$ min.

Multiple choice bio-chemistry cell structure membrane bound organelles cell: size and differentiation microscopy

Bacteria cell divides once in every two min and it takes 1 hr to fill half the cup. How much time it will take to fill the cup ? 
Tell me the correct answer with explanation ____________.

  1. A-58 min

  2. B-62 min

  3. C-120 min

  4. D-59 min
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
It is given that the doubling time of the given bacteria is 1 minute. It means the generation time of given bacterial cells is 60 seconds. If it takes 60 minutes to fill a cup, it will take 59 minutes to fill half the cup.
At 59th minute, the cup will be half-filled and in the 60th minute, the bacterial cell will double up and cup will be full filled.
Thus, the correct answer is '59 min.'
Multiple choice maths calculations and mental strategies 1 equations from statements forming equations from statements writing mathematical statements

A large tanker can be filled by two pipes A and B in 60 minutes and 40 minutes respectively. How many minutes will it take to fill the empty tanker if only B is used in the first-half of the time and A and B are both used in the second-half of the time?

  1. $15$
  2. $20$
  3. $27.5$
  4. $30$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Let x minute will be taken. In one minute A can fill the $\dfrac {1}{60}$ part of tanker and in one minute B can fill the $\dfrac {1}{40}$ part.
Both can fill in t
$\dfrac {t}{60}+\dfrac {t}{40}=1$
$t=\dfrac {60\times 40}{100}$
$t=24$
both can fill in one minute $\dfrac {1}{24}$ part of tanker.
$1=\left (\dfrac {x}{2}\right )\dfrac {1}{40}+\dfrac {x}{2}\left (\dfrac {1}{24}\right )$
$1=\dfrac {x}{80}+\dfrac {x}{48}$
$x=\dfrac {80\times 48}{128}=30$

Multiple choice

How many litres of water does an average 10-minute shower use?

  1. 100 litres

  2. 190 litres

  3. 150 litres

  4. 80 litres
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A standard showerhead uses about 15 to 20 litres of water per minute. Therefore, a 10-minute shower typically consumes around 150 to 200 litres, making 190 litres a highly representative average for standard non-low-flow showerheads.

Multiple choice maths operations adding and subtracting numbers using place value addition & subtraction mental additions and subtractions

Two pipes X and Y can fill a cistern in 24 min. and 32 min. respectively. If both the pipes are opened together, then after how much time Y should be closed so that the tank is full in 18 minutes?

  1. 6 min

  2. 8 min

  3. 10 min

  4. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Let Y closed pipe after a min .
Then part filled by (X+Y) in a min +Part filled by X in (18-x) 
So $a(\frac{1}{24}+\frac{1}{32})+(18-a)\frac{1}{24}= 1$
Multy by 96 
Or 4a+3a+72-4a=96
Or 3x=24
Or x=8 min