Question

The sum of the digits of a 2-digit number is 17. If we add 9 to the number, the new number obtained is a number formed by interchange of the digits. Find the number.

Answer 1

Answer:

The number is 89

Step-by-step explanation:

Let the number be xy

sum of the digits is 17

x + y = 17 —(1)

Interchange the digits = yx

(10x + y) +9 = 10y + x

9x - 9y + 9 = 0

x - y = -1 —(2)

Solving (1) & (2) by elimination method,

2x = 16

x = 8

y = 9