Odd negative DS

[Da_Gr8_Mperor]

If M is a finite set of negative integers, is the total number of integers in M an odd number?

 

(1) The product of all the integers in M is odd

(2) The product of all the integers in M is negative

 

(A) Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.

(B) Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.

© BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.

(D) EACH statement ALONE is sufficient.

(E) Statements (1) and (2) TOGETHER are NOT sufficient.

[GMAT-HELP]

Stmt 1:

Insufficient:

-1*-3* = 3 (product is odd) but the number of integers is even(2)

-1*-3*-5* = -15 (product is odd) but the number of integers is odd(3)

so inconclusive..

 

Stmt 2:

Sufficient

Product is -ve means number of -ve integers should be odd as product of even number of -ve integers will always be +ve..(above example still holds good)

 

Ans B.

 

Thanks,

GMAT-HELP

[Rachita7]

The answer is B)

 

A) If M = {-3, -7}

The product is 21 which is odd, when the number of integers is even. - Insufficient

 

B) M will always have odd integers if the product is negative, as even (negative) number of integers will always yield a positive product. - Sufficient

[manish8109]

Agree with rachita & Gmat help,

Ans should be B