Question

In a two digit number, the digit of the unit place is double the digit in the tens place. The number exceeds the sum of its digit by 18. Find the number.

Answer 1

Let the digit in the tens place of the number be x.
The digit in the units place of the number = 2x

∴ The number = 10(x) + 2x = 12x

Sum of the digits = x + 2x = 3x

Given that the number exceeds the sum of its digit by 18.

⇒ 12x = 3x + 18
⇒  9x = 18
⇒ x = 2

Therefore, the digit in the tens place is 2 and the digit in the units place is (2 x 2) i.e. 4.

So, the number is 24.