pp-T1-DS102

[Huang Hsin-Yi]

102.
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.

Ans: B

(1) product is odd表示所有數字都是odd
(2) 正負號和奇偶數沒關係
所以選A

[puja]

102.
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.

Ans: B

(1) product is odd表示所有數字都是odd
(2) 正負號和奇偶數沒關係
所以選A

它是問你所有數加起來是否為奇數個?
1)如果 5*1=5雖然也為奇數 但還是偶數個 --->不充分

2)所有負數只有當奇數個乘積才有可能為負 ----->充分

[Huang Hsin-Yi]

原來題意又弄錯了
感謝