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What is the smallest three-digit prime number?

Difficulty: Easy

Correct Answer: 101

Explanation:

Given data & approach

  • Three-digit numbers start at 100.
  • Check primality from 100 upward.

Step-by-step reasoning

100 is even ⇒ composite.101 has no divisor among primes ≤ √101 ≈ 10 (i.e., 2, 3, 5, 7): not divisible by any ⇒ prime.Therefore the smallest three-digit prime is 101.


Verification

Next candidates 102 (even), 103 (prime but larger) confirm minimality.


Common pitfalls

  • Choosing 103 (also prime) but not the smallest.
  • Assuming 111 is prime (actually 3 × 37).

Final Answer

101

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