What is the greatest common factor of 36 and 90?

The greatest common factor (GCF) of two numbers is the largest number that divides both of them without leaving a remainder.

To find the GCF of 36 and 90, we can determine the factors of each number and find the largest number that is common to both lists.

Factors of 36: 1, 2, 3, 4, 6, 9, 12, 18, 36 Factors of 90: 1, 2, 3, 5, 6, 9, 10, 15, 18, 30, 45, 90

From the lists above, we can see that the common factors of 36 and 90 are 1, 2, 3, 6, 9, and 18. The largest of these common factors is 18. Therefore, the greatest common factor of 36 and 90 is 18.