If (a-5)(b-2) =0, which of the following must be true ?
I. a=5 and b=2
II. if a is not 5, then b=2
III. if a=5, then b is not=2 Choose the correct choice from the following: A) I only B) II only C) III only D) I and II E) II and III
(a-5)(b-2)=0   So either a=5 or b=2 or both. It is 'or' not 'and', so it could be any of the three possibilities. Thus I and III are not necessarily true.   The answer is II only.
<result>B</result>
If (a-5)(b-2) =0, which of the following must be true ?
I. a=5 and b=2
II. if a is not 5, then b=2
III. if a=5, then b is not=2