Question

a number has two digits whose sum is 9 if 27 is added to the number its digits get interchanged
find the number

Answer 1

Let the two numbers be a,b.

So, The two digit number will be 10a + b, and reverse of that number = 10b + a
                                                                             
                                                                                                
Given, a + b =9                   -------------------  (i)

           10a + b - 27 = 10b + a

           a - b = 3                   --------------------  (ii)

On solving (i) and (ii), we get

    a = 6

Submit this value in (ii) on we get,

          b = 9 - 6 = 3

On submitting the value in above equation we get,

10a + b

= 10 * 6 + 3

=63


So, The number is 63.


Hope this helps!