Which of the following is a prime number?
- A.49
- B.47 ✓
- C.51
- D.45
Explanation: 47 has no factors other than 1 and itself, so it is prime; the other options can all be divided evenly by a smaller number.
Class 6 IMO Mathematics Olympiad practice · Number Sense · Factors, Multiples & Primes
← All Factors, Multiples & Primes questions