Oct 20 07:00 AM PDT  09:00 AM PDT Get personalized insights on how to achieve your Target Quant Score. Oct 22 08:00 PM PDT  09:00 PM PDT On Demand for $79. For a score of 4951 (from current actual score of 40+) AllInOne Standard & 700+ Level Questions (150 questions) Oct 23 08:00 AM PDT  09:00 AM PDT Join an exclusive interview with the people behind the test. If you're taking the GMAT, this is a webinar you cannot afford to miss! Oct 26 07:00 AM PDT  09:00 AM PDT Want to score 90 percentile or higher on GMAT CR? Attend this free webinar to learn how to prethink assumptions and solve the most challenging questions in less than 2 minutes.
Author 
Message 
TAGS:

Hide Tags

Intern
Joined: 29 Aug 2013
Posts: 38
Location: Bangladesh
GPA: 3.76
WE: Supply Chain Management (Transportation)

If x is a positive integer, is x<16?
[#permalink]
Show Tags
12 Jan 2016, 09:34
Question Stats:
84% (01:05) correct 16% (01:18) wrong based on 223 sessions
HideShow timer Statistics
If x is a positive integer, is x<16? (1) x is less than the average (arithmetic mean) of the first ten positive integers (2) x is the square of an integer.
Official Answer and Stats are available only to registered users. Register/ Login.
_________________
Appreciate Kudos if the post seems worthwhile!



Marshall & McDonough Moderator
Joined: 13 Apr 2015
Posts: 1684
Location: India

Re: If x is a positive integer, is x<16?
[#permalink]
Show Tags
12 Jan 2016, 09:48
St1: Average of first 10 positive integers = Sum/10 = ((10/2)(1 + 10))/10 = 55/10 = 5.5 x < 5.5 > Sufficient
St2: x = Integer^2 = 1, 4, 9, 16, 25 x can be less than 16 or greater than 16 > not sufficient
Answer: A



Intern
Joined: 20 Feb 2017
Posts: 2

Re: If x is a positive integer, is x<16?
[#permalink]
Show Tags
22 Mar 2017, 04:12
Vyshak wrote: St1: Average of first 10 positive integers = Sum/10 = ((10/2)(1 + 10))/10 = 55/10 = 5.5 x < 5.5 > Sufficient
St2: x = Integer^2 = 1, 4, 9, 16, 25 x can be less than 16 or greater than 16 > not sufficient
Answer: A Could you please explain from where did you get the first formula: (10/2(1+10)/10)



Intern
Joined: 04 Mar 2017
Posts: 2

Re: If x is a positive integer, is x<16?
[#permalink]
Show Tags
01 May 2017, 03:11
Bouka2311 wrote: Vyshak wrote: St1: Average of first 10 positive integers = Sum/10 = ((10/2)(1 + 10))/10 = 55/10 = 5.5 x < 5.5 > Sufficient
St2: x = Integer^2 = 1, 4, 9, 16, 25 x can be less than 16 or greater than 16 > not sufficient
Answer: A Could you please explain from where did you get the first formula: (10/2(1+10)/10) instead of this , u can use an easier formula for average of first 10 integers= first term+ last term/2 = 1+10/2 = 11/2 = 5.5



Intern
Joined: 23 Aug 2016
Posts: 48

Re: If x is a positive integer, is x<16?
[#permalink]
Show Tags
01 May 2017, 19:48
1. Obviously sufficient, as the average of the integers between 1 and 10 is somewhere between 1 and 10 (we don't even need to know exactly where, just that it's less than 16) 2. Obviously insufficient. x could equal 1, 4, 9, 16, 25.. etc.



Intern
Joined: 18 Mar 2017
Posts: 37

Re: If x is a positive integer, is x<16?
[#permalink]
Show Tags
23 May 2017, 08:03
sealberg wrote: 1. Obviously sufficient, as the average of the integers between 1 and 10 is somewhere between 1 and 10 (we don't even need to know exactly where, just that it's less than 16) 2. Obviously insufficient. x could equal 1, 4, 9, 16, 25.. etc. The average of the first positive ten integers  but the first positive ten integers of what? Why can't the first ten integers be part of a set that, for instance, goes from 100 to 109? I was aware that (A) would be sufficient if the GMAT refers to 110 but I refused this option as the questions doesn't exactly determine the set. What do u think?



Retired Moderator
Joined: 22 Aug 2013
Posts: 1428
Location: India

Re: If x is a positive integer, is x<16?
[#permalink]
Show Tags
23 May 2017, 11:25
Bouka2311 wrote: Vyshak wrote: St1: Average of first 10 positive integers = Sum/10 = ((10/2)(1 + 10))/10 = 55/10 = 5.5 x < 5.5 > Sufficient
St2: x = Integer^2 = 1, 4, 9, 16, 25 x can be less than 16 or greater than 16 > not sufficient
Answer: A Could you please explain from where did you get the first formula: (10/2(1+10)/10) If we are given 'n' numbers in Arithmetic Progression (evenly spaced), there is a formula for their sum which is: Sum = n/2 (First term + Last term) Here we are looking at first 10 positive integers: 1, 2, 3, ....10 (these are obviously evenly spaced) So n=10, first term = 1, last term = 10 Hence sum = (10/2) (1 + 10) = 55 But average = Sum/n = 55/10 = 5.5



Retired Moderator
Joined: 22 Aug 2013
Posts: 1428
Location: India

Re: If x is a positive integer, is x<16?
[#permalink]
Show Tags
23 May 2017, 11:29
guenthermat wrote: sealberg wrote: 1. Obviously sufficient, as the average of the integers between 1 and 10 is somewhere between 1 and 10 (we don't even need to know exactly where, just that it's less than 16) 2. Obviously insufficient. x could equal 1, 4, 9, 16, 25.. etc. The average of the first positive ten integers  but the first positive ten integers of what? Why can't the first ten integers be part of a set that, for instance, goes from 100 to 109? I was aware that (A) would be sufficient if the GMAT refers to 110 but I refused this option as the questions doesn't exactly determine the set. What do u think? Hi Good query I think. I believe that when a question states 'first 10 positive integers' without giving any other set, then it means 'universal first 10 positive integers'.. which means starting from 1 and going upto 10 So first n positive integers = 1,2, 3, 4, ....n First n nonnegative integers = 0, 1, 2, 3, ... First 4 positive even numbers = 2, 4, 6, 8, First two positive multiples of 5 = 5, 10 and so on..



GMAT Club Legend
Joined: 12 Sep 2015
Posts: 4009
Location: Canada

Re: If x is a positive integer, is x<16?
[#permalink]
Show Tags
23 Jan 2019, 06:47
shapla wrote: If x is a positive integer, is x<16?
1) x is less than the average (arithmetic mean) of the first ten positive integers 2) x is the square of an integer. Target question: Is x < 16? Statement 1: x is less than the average (arithmetic mean) of the first ten positive integers Since the first ten positive integers are EQUALLY SPACED, the average = (smallest number + biggest number)/2 = (1 + 10)/2 = 5.5 So, x < 5.5 Since 5.5 < 16, we can also write: x < 5.5 < 16 From here, we can see that the answer to the target question is YES, x IS less than 16Since we can answer the target question with certainty, statement 1 is SUFFICIENT Statement 2: x is the square of an integer.There are infinitely many values of x that satisfy statement 2. Here are two: Case a: x = 4 (4 is a square of an integer, since 4 = 2²). In this case, the answer to the target question is YES, x IS less than 16Case b: x = 25 (25 is a square of an integer, since 25 = 5²). In this case, the answer to the target question is NO, x is NOT less than 16Since we cannot answer the target question with certainty, statement 2 is NOT SUFFICIENT Answer: A Cheers, Brent
_________________
Test confidently with gmatprepnow.com




Re: If x is a positive integer, is x<16?
[#permalink]
23 Jan 2019, 06:47






