Question

The digits of a two digit number differ by three. If the digits are interchange and the resulting number is added to the original number, we get 143. What can be the number.

Answer 1

Let us assume, the x is the tenth place digit and y is the unit place digit of the two-digit number. Also assume x > y

Therefore, the original two-digit number is 10x + y and reversed number is 10y + x
Given:

x - y = 3
So, y = x-3
and
Number + reversed number =143
10x + y +10y + x=143
11x+11y=143

Put y = x-3
11x+11(x-3)=143
11x+11x-33=143
22x=176
x=176/22
x=8

We know, x-y =3
8-y =3
y=5

So our original number is 10x+y = 85
85 is the original number