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?  Choose the correct choice from the following choices:
A) a/2
B) b/2
C) b/2
D) (a+b)/2
E) (b+2)/2
A and B both have to be even to fulfill the condition.   a could be = 4, 6, 8 ...., b = 2,4, ....   so a - b = 2 (Even)   a/b= 2k (Even)   a/2=2k   a = 4k   so a must be multiple of 4   now try the options   Ans. (a+b)/2
<result>D</result>
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?