# CAT Quantitative Aptitude Questions | CAT Set theory Questions - Union and Intersection

###### CAT Questions | Set theory | Union and Intersection
CAT Questions

The question is from CAT Set theory. It is about venn diagrams. We just need to draw the diagram without any mistakes to solve this one. CAT exam is known to test on basics rather than high funda ideas. CAT also tests multiple ideas in the same question, and 2IIMs CAT question bank provides you with CAT questions that can help you gear for CAT Exam CAT 2020. Set Theory (especially constructing venn diagrams) is a frequently tested topic. Make sure you know the basics from this chapter.

Question 20: In a survey it was found that 10% people don’t use Facebook, Twitter or Whatsapp.8% uses all the three. There are 15% who use Facebook and Twitter only, 20% who use Twitter and Whatsapp only and 20% who use Facebook and Whatsapp only. Number of people that use only Facebook, only Twitter and only Whatsapp are equal. If the survey was conducted on 1000 people, answer the following:

1. How many people use Whatsapp only?
1. 20
2. 9
3. 15
4. 90
2. What is the ratio of number of people that uses Whatsapp only to the people using either Whats app or Facebook or both?
1. $$frac{1}{6}\\$ 2. $\frac{25}{75}\\$ 3. $\frac{1}{3}\\$ 4. $\frac{1}{9}\\$ ## 🐤 Early Bird Offer! 4,000 off on CAT '22 Online courses Valid until 25th July #### 2IIM : Best Online CAT Coaching. ## Best CAT Coaching in Chennai #### CAT Coaching in Chennai - CAT 2021Online Batches Available Now! ### Explanatory Answer ##### Method of solving this CAT Question from Set theory: If you get the Venn Diagram right, you are halfway through !! Let the no. of people that use only Facebook = only Twitter = only Whatsapp = x Let’s construct of venn diagram: From the figure we can see that x + x + x + 8 + 20 + 20 + 15 + 10 = 100 => 3x = 100 – 73 => x = $\frac{27}{3}\\$ = 9 1. Thus the of no people who use Whatsapp only = 9% or 9 x 1000/100 = 90 2. % of people that use Whatsapp only = 9 % of people that use either Whatsapp or Facebook or both = 20 + 20 + 8 + 9 + 9 +15 = 81 Thus the ratio = $\frac{9}{81}\\$ = $\frac{1}{9}\\$ The question is "How many people use Whatsapp only?" The question is "What is the ratio of number of people that uses Whatsapp only to the people using either Whats app or Facebook or both?" ##### Hence, the answer is "90 and $\frac{1}{9}\\$" respectively. ###### 🐤 Early Bird Offer! 4,000 off on CAT '22 Online courses. Valid until 25th July ###### Already have an Account? ###### CAT Coaching in ChennaiCAT 2021Enroll at 49,000/- 44,000/- Online Classroom Batches Starting Now! ###### Best CAT Coaching in Chennai Introductory offer of 5000/- Attend a Demo Class ###### Best Indore IPM & Rohtak IPM CoachingSignup and sample 9 full classes for free. Register now! ## CAT Online Coaching | CAT Arithmetic Videos On YouTube #### Other useful sources for Arithmetic Questions | Set Theory 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
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