Question

the two digit number is such that the sum of its digit is 4 if it is added to the number its digits are reserved find the number

Answer 1

Hey Mate!!


Let the digits be x and y

Then the two-digit number is 10x + y

Given that: 10x + y = 4 (x + y) 

       10x + y = 4x + 4y

        6x = 3y

          y = 2x  --------------- 1

And 10x + y + 18 = 10y + x

Or   9y – 9x = 18 ---------------- 2

Substitute the value of y in eqⁿ 2

18x – 9x = 18

9x = 18

x = 2

Therefore  y = 2x = 2 × 2 = 4

And the number is 10x + y = 10 × 2 + 4 = 24

Hence the required number is $\bold{24}$

Thanks for the question!