Slope of line

Expert replies

ayankm: Senior | Next Rank: 100 Posts; Posts: 48; Joined: Mon Apr 19, 2010 3:08 pmFollowed by: 1 member; Location: Brazil; Thanked: 5 times; GMAT Score:660

by ayankm » Tue May 11, 2010 7:58 pm

Lines n and p lie in xy plane. Is slope of line n less than slope of line p?

I. Lines n and p intersect at (5, 1)
II. Y-intercept of line n is greater than y intercept of line p

Answer is -C-.
I fail to understand why not -B-

Like this post

Source: Beat The GMAT — Data Sufficiency | Tue May 11, 2010 7:58 pm

liferocks: Legendary Member; Posts: 576; Joined: Sat Mar 13, 2010 8:31 pmFollowed by: 1 member; Thanked: 97 times

by liferocks » Tue May 11, 2010 8:17 pm

slope of any line is y1-y2/x1-x2 where x1,y1 and x2,y2 are two points on the line.

Let y intercept of n is yn and that of p is yp

hence slope of n y2-yn/x2...n passes through 0,yn and x2,y2
slope of p y1-yp/x1...n passes through 0,yp and x1,y1

option 2 says yn>yp..but unless we know the values of x1,y1 and x2,y2 we cannot conclude that y2-yn/x2 >y1-yp/x1 or vice versa

from 1 we get x1,y1 or x2,y2 is 5,1..hence we can check the slope

neither of the statements is sufficient
ans option C

Let me know if this clarifies..else I will try to put a graphical explanation

"If you don't know where you are going, any road will get you there."
Lewis Carroll

Like this post

[email protected]: Junior | Next Rank: 30 Posts; Posts: 27; Joined: Mon Apr 26, 2010 9:30 pm; Location: Johannesburg, South Africa

by [email protected] » Thu May 13, 2010 2:39 pm

ayankm wrote:Lines n and p lie in xy plane. Is slope of line n less than slope of line p?

I. Lines n and p intersect at (5, 1)
II. Y-intercept of line n is greater than y intercept of line p

Answer is -C-.
I fail to understand why not -B-

Like this post

[email protected]: Junior | Next Rank: 30 Posts; Posts: 27; Joined: Mon Apr 26, 2010 9:30 pm; Location: Johannesburg, South Africa

by [email protected] » Thu May 13, 2010 2:42 pm

ayankm wrote:Lines n and p lie in xy plane. Is slope of line n less than slope of line p?

I. Lines n and p intersect at (5, 1)
II. Y-intercept of line n is greater than y intercept of line p

Answer is -C-.
I fail to understand why not -B-

:roll:

just combine the two statements.

the two lines do meet and they touch y-axis at different points. you can definitely answer this question with this information.

ANSWER (C)

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