Question

The digit at tens place is twice the digit at unit place in a two digit number. The number formed by interchanging the digits is 18 less than the original number. Find the two digit number. Only one variable is allowed.​

Answer 1

Answer:

let the ten's digit be x and unit digit be y.

Then

ATQ,

=> x = 2y

And

=> 10x + y - 18 = 10y + x

=> 9x - 9y = 18

=> x - y = 2

=> 2y - y = 2

=> y = 2

Thus x = 4

Original Number = 42