Q and R are two-digit positive integers that have the same digits but in reverse order. If the positive difference between Q and R is less than 30, what is the greatest possible value of Q minus R?	Choose the correct answer.
A) 23 B) 24 C) 25 D) 26 E) 27

Rationale: a two - digit integer ` ` ab ' ' can be expressed algebraically as 10 a + b . q - r = ( 10 a + b ) - ( 10 b + a ) = 9 ( a - b ) < 30 . the greatest multiple of 9 which is less than 30 is 27 . the answer is e .
Answer: E