Question

The sun of the 2 digits of a certain number is 5. If 9 is added to the original number, the new number will have the original digits reversed. Find the number

Answer 1

23

Explanation:

Assume the digits are

1, 4 or 2,3

The number can be 14, 41, 23, 32

Test each one:

14 + 9 = 23 does not work

41 + 9 = 50 does not work

23 + 9 = 32 works

32 + 9 = 41 does not work