CAT Quantitative Aptitude Questions | CAT Time and Work questions

CAT Questions | Time and work | Pipes and Cisterns

The question is from Pipes and Cisterns: Pipe flow rate. Flow rates of A and B together and of A is given and we need to find out the flow rate of B. Note: Sum of the rate of flow of individual pipes gives the combined flow rate. Mathematicians are creatures of habit. This topic has been called Pipes and Cisterns because someone named it like it long ago. Pipes and Tanks would be much better - at least makes it sound like wartime.

Question 11: Pipe A can fill a tank in 12 hours. When it works along with Pipe B, it can fill the tank in 8 hours. In how many hours can pipe B fill the same tank independently?

  1. 8 hrs
  2. 12 hrs
  3. 24 hrs
  4. 16 hrs

Last day to avail 🎉 Flat ₹ 12,000 off on our CAT '24 & '25 Live Courses!


Register Now

🎉 2IIM CAT Revision Course 2024: 100+ Hours of Intensive Prep and everything is covered—Join Now!!! 🎉


Register Now

Best CAT Online Coaching
Try upto 40 hours for free
Learn from the best!


2IIM : Best Online CAT Coaching.


Best CAT Coaching in Chennai


CAT Coaching in Chennai - CAT 2022
Limited Seats Available - Register Now!


Explanatory Answer

Method of solving this CAT Question from Pipes Cisterns and Work Time: Sum of the rate of flow of individual pipes gives the combined flow rate

Let the capacity of the tank be C.
Rate of Pipe A = \\frac{C}{A}\\)
Rate of Pipe B = \\frac{C}{B}\\)
Rate of Pipe A and Pipe B together = \\frac{C}{A}\\) + \\frac{C}{B}\\) = \\frac{C}{8}\\)
\\frac{C}{12}\\) + \\frac{C}{B}\\) = \\frac{C}{8}\\)
\\frac{C}{B}\\) = \\frac{C}{8}\\) - \\frac{C}{12}\\) = \\frac{C}{24}\\)
Pipe B independently will take 24 hours to fill the tank.

The question is "In how many hours can pipe B fill the same tank independently?"

Hence, the answer is "24 hrs".

Choice C is the correct answer.


CAT Online Coaching | CAT Arithmetic Videos On YouTube


Other useful sources for Arithmetic Questions | Pipes Cisterns; Time and Work Sample Questions


CAT Questions | CAT Quantitative Aptitude

CAT Questions | CAT DILR

CAT Questions | Verbal Ability for CAT


Where is 2IIM located?

2IIM Online CAT Coaching
A Fermat Education Initiative,
58/16, Indira Gandhi Street,
Kaveri Rangan Nagar, Saligramam, Chennai 600 093

How to reach 2IIM?

Phone: (91) 44 4505 8484
Mobile: (91) 99626 48484
WhatsApp: WhatsApp Now
Email: prep@2iim.com