BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

manhattan-ps 7

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
User avatar
Legendary Member
Posts: 1309
Joined: Wed Mar 17, 2010 11:41 pm
Thanked: 33 times
Followed by:5 members

manhattan-ps 7

by pradeepkaushal9518 » Sat Sep 11, 2010 4:10 am
x, y, and z are positive integers. The average (arithmetic mean) of x, y, and z is 11. If z is two greater than x, which of the following must be true?
I. x is even
II. y is odd
III. z is odd

I only
II only
III only
I and II only
I and III only
A SMALL TOWN GUY
Top
Source: — Problem Solving |

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 1179
Joined: Sun Apr 11, 2010 9:07 pm
Location: Milpitas, CA
Thanked: 447 times
Followed by:88 members

by Rahul@gurome » Sat Sep 11, 2010 4:52 am
(x + y + z)/3 = 11 or x + y + z = 33
z = 2 + x
Then, x + y + (2 + x) = 33 or 2x + y = 31
If x is EVEN, y is ODD, then 2(EVEN) + ODD = ODD; this is true
If x is EVEN, y is EVEN, then 2(EVEN) + EVEN = EVEN; not true
If x is ODD, y is ODD, then 2(ODD) + ODD = EVEN + ODD = ODD; this is true.
If x is ODD, y is EVEN, then 2(ODD) + EVEN = EVEN + EVEN = EVEN; not true

Therefore, x may be even or odd, but y is odd is true. z may be even or odd, as z depends on x.
So, only II is true.

The correct answer is [spoiler](B)[/spoiler].
Rahul Lakhani
Quant Expert
Gurome, Inc.
https://www.GuroMe.com
On MBA sabbatical (at ISB) for 2011-12 - will stay active as time permits
1-800-566-4043 (USA)
+91-99201 32411 (India)
Top
Senior | Next Rank: 100 Posts
Posts: 74
Joined: Sun Sep 05, 2010 3:11 pm
Thanked: 3 times

by klmehta03 » Sat Sep 11, 2010 9:16 am
Agree the answer is B
Top
Post new topic Post Reply
• Page 1 of 1