Let the original number be = 10x + y. where x > y According to the question, 10x + y – 10y – x = 9 ⇒ x – y = 1 ..... (i) x + y = 13 ..... (ii) Adding equation (i) and (ii), 2x = 14 ⇒ x =
14
2
= 7 From equation (i), 7 – y = 1 ⇒ y = 6 ∴ Number = 76