Question

the sum of the digit of a two digit number is 10 if the number formed by reserving the digit is less than the original number by 36 find the number

Answer 1

The tens digits of a 2-digit number is less than the ones digit by 3. If the digits are reversed, the difference between the two number is 27.

Answer 2

Let x = units digit
y = ten's digit
The value of the number is x + 10y
The new value after reversing the digits is 10x + y 
Equations:
x + y = 10 and
10x + y = x + 10y - 36 or 9x - 9y = -36 or x - y = -4
Add the 2 equations, the result is 2x = 6
so x = 3 and y = 7
The original number is 73