# CAT Quantitative Aptitude Questions | CAT Geometry - Mensuration Problems

###### CAT Questions | CAT Mensuration Questions | Length of a string

This question is from CAT Mensuration in CAT Geometry. A string is would around two circular disks. Radii of the disks are given and we need to find out the length of the string. Mensuration Questions in the CAT exam can be solved with practical approach and thought process rather than just knowing theorems from CAT Geometry. Even if one is not completely prepared for CAT Geometry exam, he or she should be able to do well in Mensuration problems tested by the CAT Exam. Knowing Mensuration formulas is important. Make sure you master Mensuration questions for CAT exam.

Question 6: A string is wound around two circular disk as shown. If the radius of the two disk are 40 cm and 30 cm respectively. What is the total length of the string?

1. 140 + 45π cm
2. 140 + 165π cm
3. 140 + 120π cm
4. 140 + 165π/2 cm

## Best CAT Coaching in Chennai

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

##### Method of solving this CAT Question from Geometry - Mensuration: What is the relation between length of the string and a Circle ( p.s. it has something do with the circumference!!).

As, tangent from an exterior point makes right angle with the radius.
=> ADXB and ODX’E are squares,
∴ AO = BO = 40 cm
OD = DE = 30 cm
Length of string wound around circle x => 270°/360° ∗ 2 ∗ π ∗ 80
= 3/4 ∗ 160π
=120π
Similarly, Length of string wound around circle x’ => 270°/360° ∗ 2 ∗ π ∗ 30
= 3/4 ∗ 30π
= 45π/2
∴ Length of the string = 80 + 60 + 120π + 45π/2 ∗ π
= 140 + 165π/2

The question is "What is the total length of the string?"

##### Hence, the answer is 140 + 165π/2 cm.

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 Preparation Online | CAT Geometry - Mensuration Videos On YouTube

#### Other useful sources for Geometry Questions | Mensuration 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