Question

a number consists of two digits. the digits at the tens place is two times the digit at the unit place. the number formed by reversing the digit is 18 less than the original number find the original number.

Answer 1

Answer:

42

Step-by-step explanation:

let the unit digit = x

tens digit = 2x

so the number is 10 * 2x + x = 21x          [∵ 2x is the tens digit ]

the number when reversed =  10 * x + 2x  = 12x

According to the question ,

21x - 18 = 12x

⇒ 21x - 12x = 18

9x = 18

x = 18/9 = 2

∴ the original number = 21x

                                     = 21 * 2 = 42