To figure out the mystery number, the biggest clue we have is the fact that the number is a double digit and the 2 integers add up to 7. We can list out the possible ways to get a sum of 7. Then we can see which is the mystery number.
0+7
1+6
2+5
3+4
With these pairs, we can automatically eliminate 0+7 because 70 is greater than 30. We can also eliminate 3+4 because 34 is even, not odd. When you flip it to 4+3, it is odd, but it is greater than 30. We can also eliminate 1+6 because 16 is even and 61 is greater than 30. Our answer is 25. 2+5=7 and 25 is odd that is less than 30.
