Register    Login    Search    Rss Feeds

Forums Home » Ask An Instructor » GMAT Math » General Math Questions


 Page 1 of 1 [ 4 posts ] 



  Print view Print view Previous topic Previous topic | Next topic Next topic
 

DS Question from OG 12

Author Message
poojaswamy
 Post subject: DS Question from OG 12
 Post Posted: Sat May 21, 2011 2:04 am 
Offline
Students


Posts: 6
Leo can buy a certain computer for p1 dollars in state A, where the sales tax is t1 percent, or he can buy the same computer for p2 dollars in state B, where the sales tax rate is t2 percent. Is the total cost of the computer greater in State A than in state B?

1. t1 > t2
2. p1t1 > p2t2

This is how I approached this problem.

Need to check if p1+p1t1/100 > p2+p2t2/100

Statement 1 - IS
Stmt 2 - IS

1+2 - t1>t2, p1t1>p2t2 implies p1>p2 (since we definitively know t1 and t2 are positive). So, we have p1>p2 and p1t1>p2t2, implying p1+p1t1/100 > p2+p2t2/100.

Can mgmat staff please help?
OA - E
Top 
RonPurewal
 Post subject: Re: DS Question from OG 12
 Post Posted: Sat May 21, 2011 8:06 am 
Offline
ManhattanGMAT Staff


Posts: 7146
poojaswamy wrote:
t1>t2, p1t1>p2t2 implies p1>p2 (since we definitively know t1 and t2 are positive).


this is not true.
for instance, 2 > 1 and (3)(2) > (4)(1) does not imply that 3 > 4.

the converse is true -- i.e., if you had t1 > t2 and p1 > p2 (all positive) then you would know that t1p1 > t2p2 -- but you can't do that the other way around.
Top 
poojaswamy
 Post subject: Re: DS Question from OG 12
 Post Posted: Sat May 21, 2011 6:33 pm 
Offline
Students


Posts: 6
Didn't expect to get a response on a weekend. You guys ROCK!!! Thanks Ron :)

poojaswamy wrote:
Leo can buy a certain computer for p1 dollars in state A, where the sales tax is t1 percent, or he can buy the same computer for p2 dollars in state B, where the sales tax rate is t2 percent. Is the total cost of the computer greater in State A than in state B?

1. t1 > t2
2. p1t1 > p2t2

This is how I approached this problem.

Need to check if p1+p1t1/100 > p2+p2t2/100

Statement 1 - IS
Stmt 2 - IS

1+2 - t1>t2, p1t1>p2t2 implies p1>p2 (since we definitively know t1 and t2 are positive). So, we have p1>p2 and p1t1>p2t2, implying p1+p1t1/100 > p2+p2t2/100.

Can mgmat staff please help?
OA - E
Top 
jnelson0612
 Post subject: Re: DS Question from OG 12
 Post Posted: Sun May 22, 2011 4:43 pm 
Offline
ManhattanGMAT Staff


Posts: 1857
:-)

_________________
Jamie Nelson
ManhattanGMAT Instructor
Top 
Display posts from previous:  Sort by  
 
 Page 1 of 1 [ 4 posts ] 





Who is online

Users browsing this forum: No registered users and 1 guest

 
 

 
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to: