If ab represents a positive two digit number, where a and b are single digit integers, which of the following cannot be true?	Choose the correct choice from the following answers:
A) a+b =9  B) (a)(b)=9  C) a-b = 9  D) b-a= 9  E) a/b = 9
(A) ab = 45 or 63 or 27   (B) ab = 33 or 19   (C) 90   (D) impossible   (E) ab = 91   (D) is impossible because 09 is not a valid two digit number --- if there's a zero in the ten's place, that's just 9, a single digit number. Therefore, no valid two digit number would satisfy (D).   ans b-a= 9
<result>D</result>
If ab represents a positive two digit number, where a and b are single digit integers, which of the following cannot be true?