Target Test Prep 20% Off Flash Sale is on! Code: FLASH20

Redeem
Target Test Prep
5-Day Free Trial
5-day free, full-access trial TTP

Available with Beat the GMAT members only code

MORE DETAILS
Target Test Prep
Magoosh
Magoosh
Study with Magoosh GMAT prep

Available with Beat the GMAT members only code

MORE DETAILS
Magoosh

DS INTEGER

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Senior | Next Rank: 100 Posts
Posts: 87
Joined: Sun Jul 24, 2011 10:36 am

DS INTEGER

by [email protected] » Thu Sep 22, 2011 8:13 am
Q: IF M AND N ARE INTEGERS, AND X= 3^N AND Y= 3^M .IS X >2Y ?

A: N= M+1
B: N= 2M
Top
User avatar
Master | Next Rank: 500 Posts
Posts: 158
Joined: Sat Sep 03, 2011 10:31 am
Thanked: 29 times
Followed by:2 members

by gmatclubmember » Thu Sep 22, 2011 8:24 am
[email protected] wrote:Q: IF M AND N ARE INTEGERS, AND X= 3^N AND Y= 3^M .IS X >2Y ?

A: N= M+1
B: N= 2M
Consider A:
x>2y=> 3^n > 2.3^(n-1) => 3^n > 2/3 * 3^n ---- sufficient.
Consider B:
x>2y => 3^2m > 2.3^m => insufficient.

So answer is A.

Cheers
Ami/-
Top
User avatar
Legendary Member
Posts: 1309
Joined: Mon Apr 04, 2011 5:34 am
Location: India
Thanked: 310 times
Followed by:123 members
GMAT Score:750

by cans » Thu Sep 22, 2011 8:29 am
X= 3^N AND Y= 3^M . IS X >2Y ??
3^n > 2*3^m ??
A) n=m+1. thus lhs = 3*3^m. as 3>2 sufficient
B) n=2M.
3^(2m) > 2* 3^m ?? or 3^m * 3^m > 2*3^m or 3^m>2???
if m=0, 1>2 false
if m=1, 3>2 true
Insufficient
IMO A
If my post helped you- let me know by pushing the thanks button ;)

Contact me about long distance tutoring!
[email protected]

Cans!!
Top
Senior | Next Rank: 100 Posts
Posts: 87
Joined: Sun Jul 24, 2011 10:36 am

by [email protected] » Thu Sep 22, 2011 11:33 pm
cans wrote:X= 3^N AND Y= 3^M . IS X >2Y ??
3^n > 2*3^m ??
A) n=m+1. thus lhs = 3*3^m. as 3>2 sufficient
B) n=2M.
3^(2m) > 2* 3^m ?? or 3^m * 3^m > 2*3^m or 3^m>2???
if m=0, 1>2 false
if m=1, 3>2 true
Insufficient
IMO A
THANKS FOR YOUR POST.
BUT WE DON'T KNOW THAT BOTH M AND N ARE POSITIVE OR NEGATIVE INTEGER. IF BOTH ARE NEGATIVE THAN I THINK THE ANSWER WOULD BE NOT SAME AS WHEN BOTH ARE POSITIVE
Top
User avatar
Master | Next Rank: 500 Posts
Posts: 181
Joined: Fri Sep 04, 2009 12:06 pm
Thanked: 17 times
Followed by:1 members

by ikaplan » Thu Sep 22, 2011 11:47 pm
If you plug-in negative values for M in the equality 3^m*3>2/3 *3^m you will realize that the equality works out both for negative numbers as well
"Commitment is more than just wishing for the right conditions. Commitment is working with what you have."
Top
Post new topic Post Reply
• Page 1 of 1