Question

(I) 217 (II) 143 (III) 214 (IV) 157 (V) 131
Four of the above numbers are alike in a certain way and form a group. Which is the one that does not belong to the group?

• A. I
• B. V
• C. I
• D. III

Hint:

In number odd-one-out questions, always check for primality, divisibility, or special mathematical properties.

Answer 1

The Correct Option is D

Step 1: Look for common property in most numbers — 217, 143, 157, and 131 are all prime numbers (cannot be divided by any number other than 1 and itself).
Step 2: Check 214 — 214 is not a prime number because it is divisible by 2 (even number).
Step 3: Conclusion on grouping — Since all others are prime numbers and 214 is composite, 214 is the odd one out.
Step 4: Eliminate incorrect options — (a) I = 217 is prime, so it belongs to the group. (b) V = 131 is prime, so it belongs. (c) I (duplicate option) is prime. Only (d) III = 214 does not fit.
Step 5: Final Answer — Option (d) III.