1. The first 3 common multiples of 4 and 6 are 12, 24, and 36. The LCM of 4 and 6 is 12.
2. Two prime numbers whose sum is also a prime number are 2 and 3. Their sum is 5, which is also a prime number.
3. The HCF of 45 and 9 is 9. The HCF of 4 and 12 is 4. The sum is 9 + 4 = 13.
4. Factors of 20: 1, 2, 4, 5, 10, 20. Factors of 28: 1, 2, 4, 7, 14, 28. The HCF is 4.
5. The HCF of 24, 36, and 60 is 12.
6. The LCM of 15 and 10 is 30. The LCM of 6 and 20 is 60. The product is 30 × 60 = 1800.
7. The LCM of 18 and 6 is 18. The HCF of 6 and 18 is 6. The quotient is 18 ÷ 6 = 3.
8. The LCM of two numbers is 143 and the HCF is 1. If one number is 11, the other number is 143 ÷ 11 = 13.
9. The LCM of 33, 11, and 66 is 66.
10. The common factors of 12, 15, and 18 in descending order are 3, 1.
Parent Tip: Review the logic above to help your child master the concept of hcf worksheet.
