1. What is the Greatest Common Factor of:

    8, 12


  2. What is the Greatest Common Factor of:

    9, 15


  3. What is the Greatest Common Factor of:

    10, 18


  4. What is the Greatest Common Factor of:

    6, 21


  5. What is the Greatest Common Factor of:

    10, 15


  6. What is the Greatest Common Factor of:

    9, 24


  7. What is the Greatest Common Factor of:

    16, 20


  8. What is the Greatest Common Factor of:

    10, 20


  9. What is the Greatest Common Factor of:

    20, 24


  10. What is the Greatest Common Factor of:

    16, 24


  11. What is the Greatest Common Factor of:

    24, 36


  12. What is the Greatest Common Factor of:

    30, 40


  13. What is the Greatest Common Factor of:

    28, 36


  14. What is the Greatest Common Factor of:

    30, 48


  15. What is the Greatest Common Factor of:

    24, 72