Question

In a two digit number the digit at the unit place is double the digit in the tens place. the number exceeds the sum of its digits by 18. find the number?​

Answer 1

Let the unit digit of the number be x and tens digit be y.

Condition 1

• The digit at the unit place is double the digit in the tens place.

Hence,

• x = 2y ...[1]

Condition 2

• The number exceeds the sum of its digits by 18.

Sum of the digits of the number = x + y

Number = 10y + x

Hence,

→ 10y + x = x + y + 18

→ 10y - y = x - x + 18

→ 9y = 18

→ y = 18/9

→ y = 2. ...[2]

Substituting the value of [2] in [1]

→ x = 2y

→ x = 2 × 2

→ x = 4

Unit digit = x = 4

Ten's digit = y = 2

Hence, the number is 24.