Looking at each number to identify what makes one different:
Option 1: 295
- Digit sum: 2+9+5=16
Option 2: 552
- Digit sum: 5+5+2=12
Option 3: 729
- Digit sum: 7+2+9=18
Option 4: 906
- Digit sum: 9+0+6=15
Checking divisibility by 3:
A number is divisible by 3 if the sum of its digits is divisible by 3.
For 295: 16÷3=5 remainder 1 (not divisible by 3)
For 552: 12÷3=4 (divisible by 3)
For 729: 18÷3=6 (divisible by 3)
For 906: 15÷3=5 (divisible by 3)
295 is the only number not divisible by 3, making it different from the others.
Therefore, the answer is Option 1: 295.