GWD6-26

[GuDon]

If r, s, and t are positive integers, is r + s + t even?
(1) r + s is even.
(2) s + t is even.

A:E

這題為什麼不是C阿
好心的大大教教我吧 感恩喔~~

[zbow]

for example ...

r = 1
s = 3
t = 5

(1) r + s = 4 ... even
(2) s+ t = 8 ... even

r + s + t = 9 ... not even...

so ... answer is E. ^^

[GuDon]

對吼
不好意思看來我問了個蠢問題呵呵
謝謝zbow大大