Question

A number consists of two digits and the digit in the ten's place exceeds that in the unit's place by 5. If 5 times the sum of the digits be subtracted from the number, the digits of the number are reversed. Then the sum of digits of the number is:

Options

• 11

• 7

• 9

• 13

Answer 1

9

Explanation:

Let the unit's digits be x

Then tan's digit be x + 5

Number = 10(x + 5) + x = 10x + 50 + x = 11x + 50

Digits are reversed = 10x + x + 5

According to question

11x + 50 – 5(2x + 5) = 10x + x + 5

x + 25 = 11x + 5

10x = 20

x = 2

Sum of digits = 2x + 5 = 2 × 2 + 5 = 9