If integers a and b are distinct factors of 30, which of the following CANNOT be a factor of 30?
I. a^b + b^2
II. (a + b)^2
III. a + b
Choose the correct choice from the following answers.
A) I only
B) II only
C) III only
D) I and II only
E) I, II, and III
Factors of 30 are 1,2,3,6,5,10,15,30.   for options 1) &amp; 3) consider a=2 and b=1 we find then 3 ,which is a factor   but for option 2) any values doesn't melts to any factor.   eg:-if we put a=3 and b=1 then (a+b)^2 =16 which is not a factor of 30   ANSWER:II only
<result>B</result>
If integers a and b are distinct factors of 30, which of the following CANNOT be a factor of 30?
I. a^b + b^2
II. (a + b)^2
III. a + b