IBPS PO Exam 2013 Solved Paper

Let one’s digit = x
ten’s digit = 2x
Number = 10 (2x) + x = 21 x
After interchange the digit number = 12 x
∴ 21x – 12x = 27
9x = 27; x = 3
∴ one’s digit = 3
Let’s digit = 2 × 3 = 6
Number = 10 × 6 + 3 = 63