Find the odd number from the alternatives given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → 2605
Option (1) 3207 — digit sum \(3+2+0+7=12\), so it is divisible by 3: \(3207=3\times1069\).
Option (2) 1308 — digit sum \(1+3+0+8=12\), divisible by 3: \(1308=3\times436\).
Option (3) 2605 — digit sum \(2+6+0+5=13\), which is not a multiple of 3, so 2605 is not divisible by 3. So 2605 is the odd one out.
Option (4) 4026 — digit sum \(4+0+2+6=12\), divisible by 3: \(4026=3\times1342\).