Prime Factors, HCF & LCM Quiz
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5 questions, one answer each
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1. Which of these is a prime number?
- A. 1
- B. 9
- C. 17
- D. 21
2. What is the prime factorisation of 48?
- A. 2⁴ × 3
- B. 2³ × 6
- C. 2² × 12
- D. 2⁵ × 3
3. What is the HCF of 24 (2³×3) and 36 (2²×3²)?
- A. 6
- B. 12
- C. 72
- D. 2
4. What is the LCM of 8 (2³) and 12 (2²×3)?
- A. 24
- B. 96
- C. 4
- D. 48
5. Two flashing lights flash every 18 and 24 seconds respectively. If they flash together now, how many seconds until they next flash together?
- A. 6
- B. 42
- C. 72
- D. 432