Which is the odd number in the following ?

The clean test here is divisibility by 4, and it works only if you check the last two digits. A number is divisible by 4 when its last two digits form a multiple of 4.

• B) 34916: last two digits 16, which is 4 x 4. Divisible by 4.
• C) 318960: last two digits 60, which is 4 x 15. Divisible by 4.
• D) 387316: last two digits 16. Divisible by 4.
• A) 876321: last two digits 21. Not a multiple of 4. This is the odd one out.

The core concept is the divisibility rule for 4, which is a basic number-property tool for reasoning and series questions. Mains rarely asks this directly, but the habit of testing a rule on the last digits quickly is useful in data handling and quantitative questions.

Trap: aspirants often count digit sums or odd digits and get stuck, because no single pattern there separates the options cleanly. Test the simple divisibility rules first (2, 3, 4, 5, 9), and check the last two digits for 4.