Question

the sum of a two digit number is 4. if the order of the digits are reversed, the result is a number that exceeds the original number by 18. find the number

Answer 1

13

Explanation:

Hello, we can write a two digit number 'ab' as 10 * a + b, where a and ba are two integer between 0 and 9.

For instance, 54= 50 + 4 = 5 *10 + 4, a = 5 b = 4, right?

The sum of a two digit number is 4.

a + b = 4

If the order of the digits are reversed, the result is a number that exceeds the original number by 18.

10b + a = 10a + b + 18

9b = 9a + 18

b = a + 2

We can replace in the first equation,

a + a + 2 = 4

2a = 2

a = 1

and then, b = 3

So the number is 13.

thank you