Answer:
35
Step-by-step explanation:
Numbers that add up to 8 and number combinations
0 and 8: 80, 08
1 and 7: 17, 71
2 and 6: 26, 62
3 and 5: 35, 53
4 and 4: 44
Since the number must be between 25 and 40, the only possible numbers are 26 and 35
Since 26 is not the answer, the number is 35