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• ### $450 Tuition Credit & Official CAT Packs FREE January 15, 2019 January 15, 2019 10:00 PM PST 11:00 PM PST EMPOWERgmat is giving away the complete Official GMAT Exam Pack collection worth$100 with the 3 Month Pack ($299) • ### The winning strategy for a high GRE score January 17, 2019 January 17, 2019 08:00 AM PST 09:00 AM PST Learn the winning strategy for a high GRE score — what do people who reach a high score do differently? We're going to share insights, tips and strategies from data we've collected from over 50,000 students who used examPAL. # What is the value of the positive integer n ?  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics Author Message TAGS: ### Hide Tags Math Expert Joined: 02 Sep 2009 Posts: 52108 What is the value of the positive integer n ? [#permalink] ### Show Tags 03 Jan 2014, 05:17 1 8 00:00 Difficulty: 5% (low) Question Stats: 79% (00:58) correct 21% (01:09) wrong based on 532 sessions ### HideShow timer Statistics The Official Guide For GMAT® Quantitative Review, 2ND Edition What is the value of the positive integer n ? (1) n^4 < 25 (2) $$n\neq{n^2}$$ Data Sufficiency Question: 18 Category: Arithmetic Arithmetic operations Page: 154 Difficulty: 600 GMAT Club is introducing a new project: The Official Guide For GMAT® Quantitative Review, 2ND Edition - Quantitative Questions Project Each week we'll be posting several questions from The Official Guide For GMAT® Quantitative Review, 2ND Edition and then after couple of days we'll provide Official Answer (OA) to them along with a slution. We'll be glad if you participate in development of this project: 1. Please provide your solutions to the questions; 2. Please vote for the best solutions by pressing Kudos button; 3. Please vote for the questions themselves by pressing Kudos button; 4. Please share your views on difficulty level of the questions, so that we have most precise evaluation. Thank you! _________________ Math Expert Joined: 02 Sep 2009 Posts: 52108 Re: What is the value of the positive integer n ? [#permalink] ### Show Tags 03 Jan 2014, 05:17 2 SOLUTION What is the value of the positive integer n ? Notice that we are told that n is a $$positive integer$$. (1) n^4 < 25. Since n is a positive integer, then n can be 1 or 2. Not sufficient. (2) $$n\neq{n^2}$$ --> $$n)\neq{1}$$. Not sufficient. (1)+(2) Since from (2) $$n)\neq{1}$$, then from (1) n=2. Sufficient. Answer: C. _________________ Senior Manager Joined: 06 Aug 2011 Posts: 336 Re: What is the value of the positive integer n ? [#permalink] ### Show Tags 03 Jan 2014, 11:24 2 Bunuel wrote: The Official Guide For GMAT® Quantitative Review, 2ND Edition What is the value of the positive integer n ? (1) n^4 < 25 (2) $$n\neq{n^2}$$ Data Sufficiency Question: 18 Category: Arithmetic Arithmetic operations Page: 154 Difficulty: 600 GMAT Club is introducing a new project: The Official Guide For GMAT® Quantitative Review, 2ND Edition - Quantitative Questions Project Each week we'll be posting several questions from The Official Guide For GMAT® Quantitative Review, 2ND Edition and then after couple of days we'll provide Official Answer (OA) to them along with a slution. We'll be glad if you participate in development of this project: 1. Please provide your solutions to the questions; 2. Please vote for the best solutions by pressing Kudos button; 3. Please vote for the questions themselves by pressing Kudos button; 4. Please share your views on difficulty level of the questions, so that we have most precise evaluation. Thank you! Its C.. STATEMENT 1===== n4<25.. n can 1 AND 2.. 1^4=1 that is less than 25. N2=16 that is less than 25. Statement 2====== n is not equal to n2 .. from this we can say this n is not 1..bt we dont knw n cud be 2 ,3 or 4 not sufficient. Both statement togather are sufficient. n is 2 because from statement 1 we got that n cud be 2 or 1 ..and from statement 2 we got that n can not 1..so n is 2..sufficient. _________________ Bole So Nehal.. Sat Siri Akal.. Waheguru ji help me to get 700+ score ! Manager Status: GMATting Joined: 21 Mar 2011 Posts: 105 Concentration: Strategy, Technology GMAT 1: 590 Q45 V27 Re: What is the value of the positive integer n ? [#permalink] ### Show Tags 04 Jan 2014, 09:31 1. The 2 numbers that have 4th power less than 25 are 1 and 2; 1 and 16 2. From this, n is anything but 1; Both together, clearly, gives the value as 2. Sufficient. (C). Director Joined: 03 Feb 2013 Posts: 848 Location: India Concentration: Operations, Strategy GMAT 1: 760 Q49 V44 GPA: 3.88 WE: Engineering (Computer Software) Re: What is the value of the positive integer n ? [#permalink] ### Show Tags 05 Jan 2014, 10:33 1 Bunuel wrote: The Official Guide For GMAT® Quantitative Review, 2ND Edition What is the value of the positive integer n ? (1) n^4 < 25 (2) $$n\neq{n^2}$$ Statement 1) n^4 < 25, both the values of n = 1 or 2 satisfies the statement. Not Sufficient. Statement 2) n is not equal to n^2. We cannot determine any value of n from this statement. Not Sufficient. Combining the two statement, only n = 2 satisfies both the condition. Hence Option C) _________________ Thanks, Kinjal My Application Experience : http://gmatclub.com/forum/hardwork-never-gets-unrewarded-for-ever-189267-40.html#p1516961 Linkedin : https://www.linkedin.com/in/kinjal-das/ Please click on Kudos, if you think the post is helpful Math Expert Joined: 02 Sep 2009 Posts: 52108 Re: What is the value of the positive integer n ? [#permalink] ### Show Tags 05 Jan 2014, 11:12 SOLUTION What is the value of the positive integer n ? Notice that we are told that n is a $$positive integer$$. (1) n^4 < 25. Since n is a positive integer, then n can be 1 or 2. Not sufficient. (2) $$n\neq{n^2}$$ --> $$n)\neq{1}$$. Not sufficient. (1)+(2) Since from (2) $$n)\neq{1}$$, then from (1) n=2. Sufficient. Answer: C. _________________ Math Revolution GMAT Instructor Joined: 16 Aug 2015 Posts: 6798 GMAT 1: 760 Q51 V42 GPA: 3.82 What is the value of the positive integer n ? [#permalink] ### Show Tags 19 Sep 2015, 23:59 Forget conventional ways of solving math questions. In DS, Variable approach is the easiest and quickest way to find the answer without actually solving the problem. Remember equal number of variables and independent equations ensures a solution. What is the value of the positive integer n ? (1) n^4 < 25 (2) n≠n 2 In the original condition there is 1 variable (n) and in order to match the number of variable and equation, we need 1 equation. Since there is 1 each in 1) and 2), D has high probability of being the answer. in case of 1), n=1,2 the answer is not unique, therefore the condition is NOT sufficient. in case of 2), n=2,3.4.... and the answer is not unique. therefore the condition is NOT sufficient. Using both 1) & 2) together, the answer is unique and therefore the conditions are sufficient. Thus the answer is C Normally for cases where we need 1 more equation, such as original conditions with 1 variable, or 2 variables and 1 equation, or 3 variables and 2 equations, we have 1 equation each in both 1) and 2). Therefore D has a high chance of being the answer, which is why we attempt to solve the question using 1) and 2) separately. Here, there is 59 % chance that D is the answer, while A or B has 38% chance. There is 3% chance that C or E is the answer for the case. Since D is most likely to be the answer according to DS definition, we solve the question assuming D would be our answer hence using 1) and 2) separately. Obviously there may be cases where the answer is A, B, C or E. _________________ MathRevolution: Finish GMAT Quant Section with 10 minutes to spare The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy. "Only$149 for 3 month Online Course"
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Re: What is the value of the positive integer n ?  [#permalink]

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20 Sep 2015, 06:53
MathRevolution wrote:
Forget conventional ways of solving math questions. In DS, Variable approach is the easiest and quickest way to find the answer without actually solving the problem.
Remember equal number of variables and independent equations ensures a solution.

What is the value of the positive integer n ?

(1) n^4 < 25
(2) n≠n 2

In the original condition there is 1 variable (n) and in order to match the number of variable and equation, we need 1 equation. Since there is 1 each in 1) and 2), D has high probability of being the answer.

in case of 1), n=1,2 the answer is not unique, therefore the condition is NOT sufficient.
in case of 2), n=2,3.4.... and the answer is not unique. therefore the condition is NOT sufficient.
Using both 1) & 2) together, the answer is unique and therefore the conditions are sufficient. Thus the answer is C

Normally for cases where we need 1 more equation, such as original conditions with 1 variable, or 2 variables and 1 equation, or 3 variables and 2 equations, we have 1 equation each in both 1) and 2). Therefore D has a high chance of being the answer, which is why we attempt to solve the question using 1) and 2) separately. Here, there is 59 % chance that D is the answer, while A or B has 38% chance. There is 3% chance that C or E is the answer for the case. Since D is most likely to be the answer according to DS definition, we solve the question assuming D would be our answer hence using 1) and 2) separately. Obviously there may be cases where the answer is A, B, C or E.

Hi,
using 1 and 2 separately is true for any of the options... be it A,B,C,D,E..
i do not think the observation of any two equations given would be the same.. equality and inequality of equations will have a great say on the possiblity of that equation giving us the answer so 59% may not be true for eq using < or >...
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1) Absolute modulus : http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372
2)Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html
3) effects of arithmetic operations : https://gmatclub.com/forum/effects-of-arithmetic-operations-on-fractions-269413.html

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Re: What is the value of the positive integer n ?  [#permalink]

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24 May 2018, 07:04
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