# CAT Quantitative Aptitude Questions | CAT Time and Work questions

###### CAT Questions | Time and work | Pipes Cisterns

The question is from Pipes and Cisterns: Fill pipes and Drain Pipes. Again a question on possible values. How many fill and drain pipes required to fill the tank in 'x' hours? Find a complete "Null System". Work on the question after that.

Question 5: A fill pipe can fill a tank in 20 hours, a drain pipe can drain a tank in 30 hours. If a system of n pipes (fill pipes and drain pipes put together) can fill the tank in exactly 5 hours, which of the following are possible values of n (More than one option could be correct)?

1. 32
2. 54
3. 29
4. 40
1. 1 and 2 only
2. 1 and 3 only
3. 2 and 4 only
4. 2 and 3 only

## Best CAT Coaching in Chennai

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

##### Method of solving this CAT Question from Pipes Cisterns and Work Time: Find a complete "Null System". Work on the question after that.

2 fill pipes cancel out 3 drain pipes. Plus, you need an additional 4 fill pipes fill the tank in 5 hours. so the answer has to be 5k + 4.
Both 54 and 29 are possible.

The question is "which of the following are possible values of n?"

##### Hence, the answer is "2 and 3 only".

Choice D is the correct answer.

###### CAT Coaching in ChennaiCAT 2024

Classroom Batches Starting Now! @Gopalapuram and @Anna nagar

###### Best CAT Coaching in Chennai

Attend a Demo Class

## CAT Online Coaching | CAT Arithmetic Videos On YouTube

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

##### 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