GMAT Prep Geometry??

Expert replies

dferm: Master | Next Rank: 500 Posts; Posts: 446; Joined: Thu Jul 26, 2007 1:07 pm; Thanked: 6 times

by dferm » Mon Apr 28, 2008 12:45 pm

If a and b are positive numbers, what are the coordinates of the midpoint of line segment CD in the xy-plane?

(1) The coordinates of C are (a, 1-b)
(2) The coordinates of D are (1-a, b)

Please Help...

Thanks..

Like this post

Source: Beat The GMAT — Data Sufficiency | Mon Apr 28, 2008 12:45 pm

tmmyc: Senior | Next Rank: 100 Posts; Posts: 72; Joined: Mon Mar 10, 2008 10:29 am; Thanked: 25 times

by tmmyc » Mon Apr 28, 2008 3:47 pm

Point 1: (x1, y1)
Point 2: (x2, y2)
Midpoint: ( (x1+x2)/2 , (y1+y2)/2 )

Statement 1: No information about D.
Statement 2: No information about C.

Together:
( (a+1-a)/2 , (1-b+b)/2 ) = (1/2, 1/2)
Sufficient

Head-to-Head Analysis: Veritas Prep versus Manhattan GMAT

Like this post

Post new topic Post Reply

• Page 1 of 1

GMAT Course Reviews

560 reviews

1168 reviews

431 reviews

359 reviews

147 reviews

5/5

5 Star (560 Reviews)

"Target Test Prep is the closest to the official version of the GMAT exam, about 99% accuracy in terms of the quality and quantity of information. The course has excellently created singular sets of focused lessons and tests for every possible topic that one could come across in the official GMAT exam."

"The TTP course maximizes the efficiency of the time you spend studying. It will take time and effort but I could almost guarantee that if you complete the course exactly as it is laid out you will get an amazing score. They also have a very responsive team willing to help with any questions you might have."

"TTP has two things that I think no other test prep company offers: A teaching approach that reinforces understanding and an attitude that will give you the mental preparedness needed to succeed on the test. TTP gives you a deep understanding of the concept you need to know while teaching you how to think."

Write a Review