Question

Which statement is true?

A. the greatest common factor of 10 and 14 is 5.
B. the greatest common factor of 10 and 15 is 5.
C. the greatest common factor of 13 and 21 is 3.
D. the greatest common factor of 14 and 21 is 3.

Answer 1

Option B

Explanation:

Let's check each option one by one.

A) The greatest common factor of 10 and 14 is 5.

Write down the factors of 10 and 14.

⇒ Factors of 10: 1, 2, 5, 10

⇒ Factors of 14: 1, 2, 7, 14

We can see here that the GCF is "1" as it is the greatest factor of 10 and 14.

Hence, option A is incorrect.

B) The greatest common factor of 10 and 15 is 5.

Write down the factors of 10 and 15.

⇒ Factors of 10: 1, 2, 5, 10

⇒ Factors of 15: 1, 3, 5, 15

We can see here that the GCF is "5" as it is the greatest factor of 10 and 15.

Hence, option B is correct.

C) The greatest common factor of 13 and 21 is 3.

Write down the factors of 13 and 21.

⇒ Factors of 13: 1 and 13

⇒ Factors of 21: 1, 3, 7, 21

We can see here that the GCF is "1" as it is the greatest factor of 13 and 21.

Hence, option C is incorrect.

D) The greatest common factor of 14 and 21 is 3.

Write down the factors of 14 and 21.

⇒ Factors of 14: 1, 2, 7, 14

⇒ Factors of 21: 1, 3, 7, 21

We can see here that the GCF is "7" as it is the greatest factor of 14 and 21.

Hence, option D is incorrect.

Thus, Option B is correct.

Answer 2

B. the greatest common factor of 10 and 15 is 5.

Explanation:

A. is worg 14 cannot be divided by 5

C. is wrong 13 cannot be divided by 3

D. is wroing 14 cannot be divided by 3

I mean they all can but you won't get the whole numbers only fractions.