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

Redeem

Reject a Value For K

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Junior | Next Rank: 30 Posts
Posts: 21
Joined: Sun Sep 07, 2008 1:30 pm
Thanked: 2 times

Reject a Value For K

by gdrea3 » Mon Sep 08, 2008 4:14 pm
Taken from MGMAT CAT practice test:
If x is an integer, then x(x – 1)(x – k) must be evenly divisible by three when k is any of the following values EXCEPT
A) -4
B) -2
C) -1
D) 2
E) 5

correct answer is B but I don't understand how to approach this problem (I randomly guessed)..thanks!
Top
Source: — Problem Solving |
Senior | Next Rank: 100 Posts
Posts: 73
Joined: Thu Aug 07, 2008 7:33 pm
Thanked: 7 times
Followed by:1 members

by just_do_it » Mon Sep 08, 2008 5:24 pm
1 possible approach could be using hybrid technique of plugging in and picking numbers in the same question.

i.e plugging in the options for k and picking a value for x

for eg. let x=5
plugging values of K , you'll notice that only when K=-2 the fraction is not divisible by 3.
hence option B is correct.

hope this helps.
Top
Post new topic Post Reply
• Page 1 of 1