Question

A number consists of two digits whose sum is 9 . If 27 is subtracted from the number its digits are reversed. find the number

Answer 1

Let the tens place digit be a

Unit place digit = 9 - a

According to question,

Original number - 27 = Reversed number

=> 10a + (9-a) - 27 = 10(9-a) + a

=> 10a + 9 - a - 27 = 90 - 10a + a

=> 9a - 18 = - 9a + 90

=> 18a = 108

=> a = 6

Required number = 10 (6) + (9 - 6)

= 60 + 3

= 63

Answer 2

let the unit digit no be x
so tens digit no be 9-x
now
from question
10(9-x)+x-27=10(x)+9-x
90-10x+x-27=9x+9
63-9x=9x+9
18x=54
x=3 so unit digit no =x=3 and tens digit no =9-3=6
so the no =6(10)+3=63 Answer