Question

A number consist of two digits whose sum is 9 if 27 is added to the number the digits are reversed find the number

Answer 1

The 2digit no. is 36

Answer 2

hi

let the number be xy

tens place =10x

ones place = y

now sum is 9

y + x =9

x = 9 -y

if 27 is added to the number the digits are reversed

10x + y +27 = 10y +x

10x +y - 10y -y = -  27

9x - 9y = 27

x - y = -3
since 

x +y = 9

and 

x - y = -3

adding both

2x = 6

x = 3

now x +y = 9

3 +y = 9

y = 6

so the number is  36

hope it helps u

;)