GWD20-36

[adamela]

If a and b are positive integers such that (a-b) and a/b are both even integers, which of the following must be an odd integer?

A. a/2
B. b/2
C. (a+b)/2
D. (a+2)/2
E. (b+2)/2

Answer：D

I can't figure out how to answer it!
Who can explain it?
TKS!

[fsab00037748]

http://www.formosamba.com/phpBB3/viewtopi ... 2Bb%29%2F2

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