Step-by-step explanation:
Let A be the tens digit of the number and B be the ones digit.
We have A + B = 10 and 10A + B - 36 = 10B + A.
=> A + B = 10 and 9A - 36 = 9B
=> A + B = 10 and A - 4 = B
=> A + B = 10 and A - B = 4
Therefore 2A = 10 + 4 = 14,
A = 7 and B = 10 - 7 = 3.
Hence the number is 73.