6 — Greatest Common Factor

Greatest Common Factor

Solution & Explanation · ID: 92DC4D1C

Question

Find the GCF of 18, 24, and 30.

Hint

Find factors that are common to all three numbers.

Concept

To find the GCF of three numbers, we find all factors of each number and identify the largest factor that appears in all three lists.

Show Answer

6

Show Solution
1

List all factors of 18: 1, 2, 3, 6, 9, 18

2

List all factors of 24: 1, 2, 3, 4, 6, 8, 12, 24

3

List all factors of 30: 1, 2, 3, 5, 6, 10, 15, 30

4

Find common factors in all three lists: 1, 2, 3, 6

5

The greatest common factor is 6

Three columns showing factors. Left column labeled '18:' lists 1, 2, 3, 6, 9, 18. Middle column labeled '24:' lists 1, 2, 3, 4, 6, 8, 12, 24. Right column labeled '30:' lists 1, 2, 3, 5, 6, 10, 15, 30. Common factors 1, 2, 3, and 6 are circled in all three columns. The number 6 is highlighted as the GCF.