The sum of the digits of a two-digit number is 18. If the digits are reversed, the number remains the same. Find the number.

Answer 1

If you reverse the digits of a two digit number, the sum of those digits will always remain the same.

for example, the sum of the two digits of the following numbers always remains the same when reversed:

36 and 63 sum to 9

48 and 84 sum to 12

So instead of thinking about what 2 digit numbers sum to 18, think what two single digit numbers add up to 18

The only two single digit numbers that add up to 18 are 9 and 9.

So, your two digit number is 99