Question

Determine whether or not each number is a common factor of 144 and 240. Try to use different methods, and show your work. a) 2 b) 3 c) 10 d) 48 e) 120

Answer 1

Explanation:

2| 144

2| 72

2| 36

2| 18

3| 9

| 3

144=2×2×2×2×3×3

2 | 240

2 | 120

2 | 60

2 | 30

3 | 15

| 5

240=2×2×2×2×3×5

greatest common factor=2×2×2×2×3=48

a. 2 divides both ,so common factor

b. 3 divides both ,so common factor

c. 10 does not divide 144 so not a common factor.

d.48 divides both hence a common factor.

e. 120 does not divide 144 therefore not a common factor.