# CAT Quantitative Aptitude Questions | CAT Algebra - Progressions questions

###### CAT Questions | Algebra | Progressions - Geometric Progressions CAT Questions

The question is about CAT Geometric Progressions. A question on possible values. We need to find out the possible values of 'n' which is related to the common ratio of a GP. With some simple but very powerful ideas, one can cut down on a lot of working when it comes to progressions. For example, anchoring a progression around its middle term can be very useful. CAT Exam tests the idea of progression often in the CAT Quantitative Aptitude section and this could also be tested in DI LR section of the CAT Exam as a part of a puzzle.

Question 1: Second term of a GP is 1000 and the common ratio is r = $$frac{1}{n}\\$ where n is a natural number. Pn is the product of n terms of this GP. P6 > P5 and P6 > P7, what is the sum of all possible values of n? 1. 4 2. 9 3. 5 4. 13 ## 40 Hours of Sample classes. Signup to check now! #### 2IIM : Best Online CAT Coaching. ## Best CAT Coaching in Chennai #### CAT Coaching in Chennai - CAT 2020Online Batches Available Now! ### Explanatory Answer ##### Method of solving this CAT Question from CAT Algebra - Progressions: This question is almost a puzzle. You have to carefully consider the implications for the common ratio, and then extrapolate to the Product of n terms. Common ratio is positive, and one of the terms is positive => All terms are positive P6 = P5 * t6 => If P6 > P5, t6 > 1 P7 = P6 * t7 => If P6 > P7, t7 < 1 t6 = t2 * r4 = 1000r4; t7 = t2 * r5 = 1000r5 1000r4 > 1 and 1000r5 < 1 $\frac{1}{r^{4}}\\$ < 1000 and $\frac{1}{r^{5}}\\$ > 1000. $\frac{1}{r}\\$ = n. n4 < 1000 and n5 > 1000, where n is a natural number n4 < 1000 => n < 6 n5 > 1000 => n ≥ 4 n could be 4 or 5. Sum of possible values = 9 The question is "what is the sum of all possible values of n?" ##### Hence the answer is "9" Choice B is the correct answer. ###### Signup and Sample 9 full classes for Free ###### Best Indore IPM & Rohtak IPM CoachingSignup and sample 9 full classes for free. Register now! ###### Already have an Account? ###### CAT Coaching in ChennaiCAT 2020Enroll at 35,000/- Online Classroom Batches Starting Now! ###### Best CAT Coaching in ChennaiRegister Online, get Rs 7000/- off Attend a Demo Class ## CAT Online Preparation | CAT Algebra Videos On YouTube #### Other useful sources for Algebra Questions | Arithmetic Progressions Geometric Progressions 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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