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

Redeem

PS

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Legendary Member
Posts: 876
Joined: Thu Apr 10, 2008 8:14 am
Thanked: 13 times

PS

by ketkoag » Sat Mar 28, 2009 3:12 am
If the average (arithmetic mean) of positive integers x, y, and z is 10, what is the greatest
possible value of z ?
A. 8
B. 10
C. 20
D. 28
E. 30

OA: D
Please tell me if in question they have mentioned that there are 3 integers x, y, z like in the ques above, then how 2 of the integers could be same.
Please lemme know if the 2 integers could be same every time we come across the similar situation.
Top
Source: — Problem Solving |
User avatar
Site Admin
Posts: 2567
Joined: Thu Jan 01, 2009 10:05 am
Thanked: 712 times
Followed by:550 members
GMAT Score:770

by DanaJ » Sat Mar 28, 2009 3:22 am
The arithmetic mean of x, y and z is 10. This is why (x + y + z)/3 = 30 or x + y + z = 30.
To maximize z, you need to minimize x and y. The smallest positive integer is 1, so we make x = y = 1. This will in turn maximize z to 30 - 1 - 1 = 28.
Top
Legendary Member
Posts: 876
Joined: Thu Apr 10, 2008 8:14 am
Thanked: 13 times

by ketkoag » Sat Mar 28, 2009 3:37 am
Danaz
The question here is that whether we can take 2 integers same in this problem. i.e. x=y=1.....
Also please lemme know if in question it is mentioned that 'there are 3 different integers' then in this case you cannot take x=y=1. right??
Top
User avatar
Site Admin
Posts: 2567
Joined: Thu Jan 01, 2009 10:05 am
Thanked: 712 times
Followed by:550 members
GMAT Score:770

by DanaJ » Sat Mar 28, 2009 3:40 am
As it is written, it's perfectly fine to pick x = y. If you don't see "distinct" in the question, then there's no reason to think that x cannot equal y.

If, however, the question goes smth like "the arithmetic mean of three distinct positive integers is 30", then indeed you'd have to consider that x and y cannot be equal.
Top
Legendary Member
Posts: 876
Joined: Thu Apr 10, 2008 8:14 am
Thanked: 13 times

by ketkoag » Sat Mar 28, 2009 3:46 am
thanks danaz for the expalanation.....
Is it possible for u to chat with me online so that i can clear some general doubts. please lemme know when is it possible? or u can give me ur yahoo id so that i can chat with u.
My Yahoo id is [email protected]
Thanks again.
Top
Post new topic Post Reply
• Page 1 of 1