Answer: B — 9
Let the two-digit number A be 10a+b, where a and b are digits and $a
eq b$.
Since B is obtained by reversing the digits of A, we have:
B=10b+a
Since B is also a two-digit number, $b
eq 0$.
Now,
A−B=(10a+b)−(10b+a)=9a−9b=9(a−b)
It is given that A−B is a multiple of 27. Therefore:
9(a−b) is a multiple of 27
So, a−b must be a positive multiple of 3.
Since A>B, we have a>b. The possible values of a−b are:
3,6,9
Now count the valid digit pairs with a>b and $b
eq 0$:
For a−b=3:
(a,b)=(4,1),(5,2),(6,3),(7,4),(8,5),(9,6)
This gives 6 numbers.
For a−b=6:
(a,b)=(7,1),(8,2),(9,3)
This gives 3 numbers.
For a−b=9, the only possible pair is (9,0), but this is not allowed because B would not be a two-digit number.
Hence, the total number of possible values of A is:
6+3=9
Therefore, the correct answer is 9.