Gmat prep DS please help!!

This topic has expert replies
Source: — Data Sufficiency |

User avatar
Senior | Next Rank: 100 Posts
Posts: 56
Joined: Sat Sep 06, 2008 12:27 pm

by dnkcdnguy » Thu Feb 05, 2009 4:39 pm
My answer is A.

What is the OA?

Since the symbol represents either multiplication or addition, we can test both 1) and 2) with these functions. Also, it's important to note that K is an integer (i.e. a whole number and not a fraction).

1) 2 (+ or X) K = 3
2 + 1 = 3
K= 1
Only a fraction multiplied by 2 (i.e. 3/2) will satisfy this statement, as 2 X 3/2 = 3. However, since K is an integer then we can cancel out the multiplication and have a definite answer when using addition.

A is correct.

2) 1 (+ or X) 0 = K
1 + 0 = 1, K = 1
1 x 0 = 0, K = 0
There are two different answers for K and therefore insufficient. There's no need to combine both answers since A is sufficient on its own.

Please let me know what the OA is. Also, I'm sure there are other ways to answer this question and I look forward to other people's respsonses.
"If you fail to plan,..then you plan to fail"

User avatar
Senior | Next Rank: 100 Posts
Posts: 56
Joined: Sat Sep 06, 2008 12:27 pm

by dnkcdnguy » Thu Feb 05, 2009 4:50 pm
Nervermind..I just realized you posted the OA.. A is correct. :) :)
"If you fail to plan,..then you plan to fail"