It is currently 17 Oct 2017, 05:10

### GMAT Club Daily Prep

#### Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# GMAT math test - number properties 3 qn 10

Author Message
Manager
Joined: 24 Aug 2009
Posts: 149

Kudos [?]: 121 [0], given: 46

GMAT math test - number properties 3 qn 10 [#permalink]

### Show Tags

26 Oct 2009, 21:07
How many divisors does positive integer N has got

1)The difference between the largest and the smallest divisor of N is 21
2) N+1 has 2 divisors
OA is A.

Take statement 1, smalles divisor of any number is 1, largest divisor is 22 if the difference is 21.
Take N = 44, it has got 1,2,4,11 and 22, now take 22, it has got 1,2,11 & 22. so A is not sufficient

Take statement 2, N+1 has 2 divisors, meaning N+1 is a prime number hence not sufficient

combining A & B also is not sufficient, hence correct choice is E.

Kudos [?]: 121 [0], given: 46

CIO
Joined: 02 Oct 2007
Posts: 1218

Kudos [?]: 978 [0], given: 334

Re: GMAT math test - number properties 3 qn 10 [#permalink]

### Show Tags

27 Oct 2009, 03:07
Please note that 44's largest divisor is 44, not 22 as you stated. So, 44 can't be used as a proof for S1 insufficiency.
ISBtarget wrote:
How many divisors does positive integer N has got

1)The difference between the largest and the smallest divisor of N is 21
2) N+1 has 2 divisors
OA is A.

Take statement 1, smalles divisor of any number is 1, largest divisor is 22 if the difference is 21.
Take N = 44, it has got 1,2,4,11 and 22, now take 22, it has got 1,2,11 & 22. so A is not sufficient

Take statement 2, N+1 has 2 divisors, meaning N+1 is a prime number hence not sufficient

combining A & B also is not sufficient, hence correct choice is E.

_________________

Welcome to GMAT Club!

Want to solve GMAT questions on the go? GMAT Club iPhone app will help.
Result correlation between real GMAT and GMAT Club Tests
Are GMAT Club Test sets ordered in any way?

Take 15 free tests with questions from GMAT Club, Knewton, Manhattan GMAT, and Veritas.

GMAT Club Premium Membership - big benefits and savings

Kudos [?]: 978 [0], given: 334

Manager
Joined: 24 Aug 2009
Posts: 149

Kudos [?]: 121 [0], given: 46

Re: GMAT math test - number properties 3 qn 10 [#permalink]

### Show Tags

27 Oct 2009, 06:38
dzyubam wrote:
Please note that 44's largest divisor is 44, not 22 as you stated. So, 44 can't be used as a proof for S1 insufficiency.
ISBtarget wrote:
How many divisors does positive integer N has got

1)The difference between the largest and the smallest divisor of N is 21
2) N+1 has 2 divisors
OA is A.

Take statement 1, smalles divisor of any number is 1, largest divisor is 22 if the difference is 21.
Take N = 44, it has got 1,2,4,11 and 22, now take 22, it has got 1,2,11 & 22. so A is not sufficient

Take statement 2, N+1 has 2 divisors, meaning N+1 is a prime number hence not sufficient

combining A & B also is not sufficient, hence correct choice is E.

silly me.....it can only be 22 then.....

Kudos [?]: 121 [0], given: 46

Re: GMAT math test - number properties 3 qn 10   [#permalink] 27 Oct 2009, 06:38
Display posts from previous: Sort by

# GMAT math test - number properties 3 qn 10

Moderator: Bunuel

 Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.