The number of two digit numbers n such that the difference of n and the number formed by reversing the digits of n, is prime, is
0
Let the 2 - digit number be 10x + y where x, y are the digits in the order.Now, (10x + y ) - (10y + x ) = 9 (x - y), is always divisible by 9 or otherwise zero. Hence it cannot be a prime.