UPSC CAPF AC 2019 Paper

Let the number be 10x + y
where x < y.
Number obtained on reversing digits = 10y + x
∴ 10y + x – 10x – y = 27
⇒ 9y – 9x = 27
⇒ y – x = 3
∴ Required sum = 14 + 25 + 36 + 47 + 58 + 69 = 249