geometry-3 slight tricky question

This topic has expert replies
Source: — Problem Solving |

User avatar
Master | Next Rank: 500 Posts
Posts: 279
Joined: Mon Jun 25, 2012 10:56 pm
Thanked: 60 times
Followed by:10 members

by anuprajan5 » Tue Oct 23, 2012 10:37 pm
The question rephrased says that if point A is present, which is 2/3 the distance from Q, what is the co-ordinates of A.

Just from a visual, I would skip C and D.

Distance between P and Q is root 18 ( root((3-0)^2+(2-(-1))^2)) which equals 3 root 2.

2/3 distance of that is 2 root 2.

[spoiler]Taking choice B distance between P and A is root(4+4) = 2 root 2[/spoiler]
Regards
Anup

The only lines that matter - are the ones you make!

https://www.youtube.com/watch?v=kk4sZcG ... ata_player

User avatar
GMAT Instructor
Posts: 15539
Joined: Tue May 25, 2010 12:04 pm
Location: New York, NY
Thanked: 13060 times
Followed by:1906 members
GMAT Score:790

by GMATGuruNY » Wed Oct 24, 2012 2:07 am
Image

In the figure above, the point on segment PQ that is twice as far from P as from Q is

A) (3,1)

B) (2,1)

C) (2,-1)

D) (1.5,0.5)

E) (1,0)

Can anyone solve this in detail?
Don't calculate; use the answer choices.

The x coordinate of P is 0.
The x coordinate of Q is 3.
The midpoint between P and Q has an x coordinate of (0+3)/2 = 1.5
Thus, the x coordinate of a point closer to Q must be between 1.5 and 3.
Eliminate A, D, and E.
In answer choices B and C, x=2.
Since at x=2 line segment PQ is above the x axis, the y coordinate must be positive.
Eliminate C.

The correct answer is B.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.

As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.

For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3

User avatar
Senior | Next Rank: 100 Posts
Posts: 53
Joined: Sat Oct 29, 2011 3:49 am
Thanked: 2 times
Followed by:1 members

by gmat6087 » Wed Oct 24, 2012 2:09 am
'manpreet singh wrote:Image

kindly explain the answer?
Another approach.

total X distance 3-0=3
Total Y distance 2-(-1)=3

point lies on line such that it is twice the distance from p than from Q

ratio=2:1
divide the line into 3 equal parts:
x: division: 3/3=1 (each x segment)---eq1
Y: division: 3/3=1 (each Y segment)---eq2

2 parts from x segment= 1*2=>0+2=2 from eq1
2 parts from y segment= 1*2=>-1+1+1=1 from eq2(since y starts from -1)
so point is (2,1)

Master | Next Rank: 500 Posts
Posts: 271
Joined: Tue May 22, 2012 3:22 am
Thanked: 7 times
Followed by:3 members

by \'manpreet singh » Wed Oct 24, 2012 9:11 pm
Thanks guys,I guess i got puzzled with statement and yes answer is indeed B

Singh