Question

Determine the greatest common factor for the pair of numbers.

28, 40
Select one:
A. 16
B. 8
C. 4
D. 28

Answer 1

The greatest common factor is 4. 28 is not divisible by 16 and not divisible by 8. 40 is not divisible by 28. 28 and 40 are divisible by 4 however. 28 divided by 4 is 7. 40 divided by 4 is 10. Therefore the answer is C.. 4

Answer 2

Answer: C

Explanation:

28 40

∧ ∧

4 7 4 10

∧ ∧ ∧

2 2 2 2 2 5

28: 2 * 2 * 7

40: 2 * 2 * 2 * 5

What do they have in common? two 2s

GCF: 2 * 2 = 4