If s,u, and v are positive integers and 2s=2u+2v, which of the following must be true?
i. s>v
ii. u is not equal to v
iii. s > u  Answers
A) None B) I only C) II only D) III only E) I and III
Notice two things: 1. we are asked to find out which of the following MUST be true, not COULD be true and 2. s, u, and v are positive integers.   Given: 2s=2u+2v --&gt; s=u+v. Now, since s, u, and v are positive integers then s is more than either u or v, so I and III is always true. As for II: it's not necessarily true, for example 4=2+2.   Answer: I and III
<result>E</result>
If s,u, and v are positive integers and 2s=2u+2v, which of the following must be true?
i. s>v
ii. u is not equal to v
iii. s > u