Question

A number consists of two digits. The digit at the tens place twice that of the digits at unit place. If 18 is subtracted from the number, the digits are reversed. Find the number

Answer 1

Answer : $\bold{42}$


Explanation -

let the number of units place = x

Given : The digit at tens place twice of units place

Tens digit place = 2x (10) + 1 = 20x + 1 = 21x

Interchange the digits - 12x

Given : if 18 is subtracted from the number, the digits are reversed

According to the given question-

21x - 18 = 12x

21x - 12x = 18

9x = 18

x = 2.

The original number = 21 x = 21(2) = 42.


Hence :

Answer : $\bold{42}$