Question

The digits of two digit number differ by 3.if the digits are interchanged and the resulting number is added to the original number we get 143.what can be the original number?

Answer 1

Let us assume x and y are the two digits of the number

Therefore, two-digit number is = 10x + y and the reversed number is 10y + x

Given:

x – y = 3

x = 3 + y ------------1

Also given:

10y + x + 10x + y = 143

11x + 11y = 143

x + y = 13 -------------2

substitute the value of x from eqn 1 in eqn 2

3 + y + y = 13

3 + 2y = 13

2y = 10

y = 5

Therefore, x = 3 + y = 3 + 5 = 8

The two digit number is = 10x + y = (10 * 8) + 5 = 85

Answer 2

Answer:

Let the digits of the number be = x, y

We get to know that :

x - y = 3 ( when 'x' > 'y' ) ...(1)

Now, original number = 10x + y

Digits reversed, we get = 10y + x

According to the question now :

10x + y + 10y + x = 143

=》 x + y = 13 ...(2)

Eliminate "y" from both the equations... you get :

x = 8

y = 5

Original Number = 85