Question 414656

let unit digit number is x , tenth digit is y...

x+y = 10  ..............(1)

original value of number is 10y + x 

after reversing it is 10x + y 

10y +x -( 10x +y ) = 36 

=> 9y - 9x = 36 

=> y - x = 4   (dividing by 4 both side)

now, add this equation to equation (1)

we find, 

2y = 14 

=> y = 7

and value of  x = 3 

so, original number is 7*10 + 3 = 73

after reversing it becomes   37