What is the HCF of 12 and 90?

The Highest Common Factor (HCF) of 12 and 90 is 6. To find the HCF, you can list the factors of both numbers and identify the largest number that is common to both lists. The factors of 12 are 1, 2, 3, 4, 6, and 12, while the factors of 90 are 1, 2, 3, 5, 6, 9, 10, 15, 18, 30, 45, and 90. The largest number that appears in both lists is 6, making it the HCF.