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

Redeem

GMAT Prep

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Senior | Next Rank: 100 Posts
Posts: 30
Joined: Thu Feb 22, 2007 5:56 pm
Location: Seattle

GMAT Prep

by josephcho77 » Mon Oct 29, 2007 10:55 pm
If X is a positive number less than 10, is Z greater than the average of X and 10?

1) On the number line, Z is closer to 10 than it is to X
2) Z=5X



My answer is E but OA is A.
How can A be the answer?
If Z=9 ans X=8, Z is same as the average of X and 10
If Z=9 and X=6, Z is greater than the average of X and 10
If Z=2 and X=1, Z is less than the average of X and 10

Z is closer to 10 in all above case but can be same, greater, or less than the average of X and 10. What am I missing?
Top
Source: — Data Sufficiency |
Legendary Member
Posts: 645
Joined: Wed Sep 05, 2007 4:37 am
Location: India
Thanked: 34 times
Followed by:5 members

by camitava » Tue Oct 30, 2007 1:10 am
josephcho77, IMO A. Refer the approach below -


|-------------------------------------------------------------------------|
X Z 10

Now if Z is closer to 10 than X, (10 + X) / 2 should be some thing less than Z. So option - I gives the answer to the question. Are u getting me? Even if u take an example -
X = 1 and Z = 9
So (X + 10) / 2 = 5.5 where Z > 5.5. So option - I gives the answer.
Correct me If I am wrong


Regards,

Amitava
Top
Master | Next Rank: 500 Posts
Posts: 460
Joined: Sun Mar 25, 2007 7:42 am
Thanked: 27 times

by samirpandeyit62 » Tue Oct 30, 2007 7:10 am
If X is a positive number less than 10, is Z greater than the average of X and 10?

1) On the number line, Z is closer to 10 than it is to X

let avg of of X & 10 be a so a will be midway between 10 & x

now since X < 10 hence the possibilty here is

x a 10 now if z is to the left a anywhere on the nos line then it will be closer to x & if z is to the right of a then only it is closer to 10 so SUFF

2) Z=5X

INSUFF

A

hope this makes sense
Regards
Samir
Top
Post new topic Post Reply
• Page 1 of 1