Another Triangle question - Kaplan - 700+

This topic has expert replies
Senior | Next Rank: 100 Posts
Posts: 87
Joined: Sat Feb 28, 2009 7:01 am
Location: India
Thanked: 2 times

Another Triangle question - Kaplan - 700+

by imhimanshu » Sun Sep 11, 2011 6:40 am
IF the sides of the triangle have lengths x,y and z,x+y =30 and y+z = 20, then which of the following could be the perimeter of the triangle.
1- 28
2- 36
3- 42
options are -
a)1 only
b)2 only
c)1 and 2 only
d)1 and 3 only
e)1,2 and 3 only
OA to follow
Thanks
Source: — Problem Solving |

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 » Sun Sep 11, 2011 8:03 am
imhimanshu wrote:IF the sides of the triangle have lengths x,y and z,x+y =30 and y+z = 20, then which of the following could be the perimeter of the triangle.
1- 28
2- 36
3- 42
options are -
a)1 only
b)2 only
c)1 and 2 only
d)1 and 3 only
e)1,2 and 3 only
OA to follow
Thanks
I: x+y+z = 28.
Since x+y=30, it is not possible that x+y+z = 28.
Eliminate any answer choice that includes I.
Eliminate A,C,D and E.

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
Master | Next Rank: 500 Posts
Posts: 496
Joined: Tue Jun 07, 2011 5:34 am
Thanked: 38 times
Followed by:1 members

by sl750 » Sun Sep 11, 2011 9:15 am
Both options 2 and 3 are possible. Are those answer choices correct?

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 » Sun Sep 11, 2011 11:12 am
sl750 wrote:Both options 2 and 3 are possible. Are those answer choices correct?
Option III is not possible.
IF the sides of the triangle have lengths x,y and z,x+y =30 and y+z = 20, then which of the following could be the perimeter of the triangle.
1- 28
2- 36
3- 42
The third side of a triangle must be less than the sum of the other 2 sides.

III: x+y+z = 42
Since x+y=30, z=12.
Since z=12 and y+z=20, y=8.
Since y=8 and x+y=30, x=22.
Thus, the 3 sides are x=22, y=8, and z=12.
Such a triangle is not possible.
Given that y+z=20, the third side (x) must be less than 20.
Thus, it is not possible that x=22.
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