gmat prep question

Is the answer B.

(1) c(d+1) is even. This could be the case when c and d is even or when c and d is odd. Hence not sufficient

(2) (c+2)(c+4) is even. This means c should be even. Hence sufficient.

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jayhawk2001: Community Manager; Posts: 789; Joined: Sun Jan 28, 2007 3:51 pm; Location: Silicon valley, California; Thanked: 30 times; Followed by:1 members

by jayhawk2001 » Mon May 28, 2007 6:25 pm

Another B

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yvonne12: Master | Next Rank: 500 Posts; Posts: 144; Joined: Wed Feb 07, 2007 4:13 pm

no

by yvonne12 » Mon May 28, 2007 7:03 pm

no the answer is c

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mendiratta: Junior | Next Rank: 30 Posts; Posts: 26; Joined: Tue May 08, 2007 8:22 pm; Thanked: 1 times

by mendiratta » Wed May 30, 2007 3:53 am

Agree with C. (Though my first guess was also B

)

1. Clearly INSUFF as explained by Prasanna.
2. This stmt guarantees that C is even in all the cases except when C = 0; this statement is true but it doesn't tells about C (because 0 is neither even nor odd)- so INSUFF.

But if we combine both, first statement tells that C is not zero. (because something multiplied by C is even).

Therefore C.

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jayhawk2001: Community Manager; Posts: 789; Joined: Sun Jan 28, 2007 3:51 pm; Location: Silicon valley, California; Thanked: 30 times; Followed by:1 members

by jayhawk2001 » Wed May 30, 2007 6:58 am

mendiratta wrote:Agree with C. (Though my first guess was also B )

1. Clearly INSUFF as explained by Prasanna.
2. This stmt guarantees that C is even in all the cases except when C = 0; this statement is true but it doesn't tells about C (because 0 is neither even nor odd)- so INSUFF.

But if we combine both, first statement tells that C is not zero. (because something multiplied by C is even).

Therefore C.

Hmm, OG quants (Green book) tells us that the sequence -4, -2, 0, 2, 4 ...
is even.

I just checked wikipedia and it says 0 is even as well.

https://en.wikipedia.org/wiki/Even_and_odd_numbers

Not sure how it can be C, given the above...