Answer:
The 2 digit number is 36.
Step-by-step explanation:
Let the 2 digits be x and y . The 2 digit number is xy.
x + y = 9........(1)
The old number can be written as 10x + y and the new number as 10y + x.
10y + x = 10x + y + 27
9x - 9y = - 27
x - y = -3 ......(2)
Adding (1) and (2) we get:
2x = 6
x = 3
and therefore y = 9-3 = 6.