10 questions · Form 1 Mathematics Bab 2: Factors and Multiples
10 questions · plays in fullscreen
Prefer reading to quizzing? All 10 questions are listed below with the answer and explanation under each one.
1. Which of the following is a common factor of 18 and 24?
Answer: A
Factors of 18: 1, 2, 3, 6, 9, 18. Factors of 24: 1, 2, 3, 4, 6, 8, 12, 24. Shared factors are 1, 2, 3, and 6.
2. Which of the following statements is FALSE?
Answer: A
1 is neither a prime nor a composite number because it only has one factor.
3. The difference between the LCM and HCF of 15 and 20 is...
Answer: A
HCF(15, 20) = 5. LCM(15, 20) = 60. Difference = 60 - 5 = 55.
4. What are all the prime factors of 30?
Answer: A
30 = 2 × 3 × 5. Note that 1 is not a prime number.
5. Which set of numbers represents the first four multiples of 7?
Answer: A
7 × 1 = 7, 7 × 2 = 14, 7 × 3 = 21, 7 × 4 = 28.
6. Find the Highest Common Factor (HCF) of 12 and 18.
Answer: A
Factors of 12: 1, 2, 3, 4, 6, 12. Factors of 18: 1, 2, 3, 6, 9, 18. The highest common factor is 6.
7. Which of the following is a common multiple of 4 and 6?
Answer: A
Multiples of 4: 4, 8, 12, 16, 20, 24... Multiples of 6: 6, 12, 18, 24... 24 is a common multiple.
8. Find the Lowest Common Multiple (LCM) of 6 and 8.
Answer: A
Multiples of 6: 6, 12, 18, 24... Multiples of 8: 8, 16, 24... The smallest common multiple is 24.
9. Find the Highest Common Factor (HCF) of 16, 24, and 32.
Answer: A
Using repeated division: 16 ÷ 8 = 2, 24 ÷ 8 = 3, 32 ÷ 8 = 4. Since 2, 3, 4 share no common factors, HCF = 8.
10. Express 72 as a product of its prime factors.
Answer: A
72 = 8 × 9 = (2 × 2 × 2) × (3 × 3) = 23 × 32.