Find the GCF of the given numbers. See Example 10. 24, 36, 40 Reference Example 10...

Find the GCF of the given numbers. See Example 10.

24, 36, 40

Reference Example 10

Find the GCF of 20, 60, and 140.

Strategy We will begin by finding the prime factorizations of 20, 60, and 140.

Why Then we can identify any prime factors that they have in common.

Solution

The prime factorizations of 20, 60, and 140 are shown below.

The circling above shows that 20, 60, and 140 have three common factors: two common factors of 2 and one common factor of 5. The GCF is the product of the circled prime factors.

GCF (20, 60, 140) = 2 · 2 · 5 = 20 Read as “The greatest common factor of 20, 60, and 140 is 20.”

Note that 20 is the greatest number that divides 20, 60, and 140 exactly.