What is the greatest common factor of 20 and 16?

Answer 1

The common factors of 16 and 20 are 1, 2, and 4.

The greatest or highest common factor is the highest number that divides exactly into two or more numbers.

16: 1, 2, 4, 8, 16

20: 1, 2, 4, 5, 10, 20

The greatest common factor for 16 and 20 is 4.

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To find using primes:

16 = 2 x 2 x 2 x 2

20 = 2 x 2 x 5

Common primes (2, 2) and 2 x 2 = 4

Answer 2

GCF(20, 16) = 4.

Answer 3

4