# Greatest Common Factor of 2 Numbers Online Quiz

Following quiz provides Multiple Choice Questions (MCQs) related to Greatest Common Factor of 2 Numbers. You will have to read all the given answers and click over the correct answer. If you are not sure about the answer then you can check the answer using Show Answer button. You can use Next Quiz button to check new set of questions in the quiz. Q 1 - The greatest common factor of 12 and 21 is

A - 3

B - 4

C - 7

D - 9

### Explanation

Step 1:

The prime factorization of 12 is

12 = 2 × 2 × 3

The prime factorization of 21 is

21 = 3 × 7

Step 2:

The greatest common factor of 12 and 21 is therefore 3.

Q 2 - The greatest common factor of 15 and 24 is

A - 2

B - 3

C - 4

D - 5

### Explanation

Step 1:

The prime factorization of 15 is

15 = 3 × 5

The prime factorization of 24 is

24 = 2 × 2 × 2 × 3

Step 2:

The greatest common factor of 15 and 24 is therefore 3.

Q 3 - The greatest common factor of 52 and 130 is

A - 24

B - 25

C - 26

D - 27

### Explanation

Step 1:

The prime factorization of 52 is

52 = 2 × 2 × 13

The prime factorization of 130 is

130 = 2 × 5 × 13

Step 2:

The greatest common factor of 52 and 130 is therefore = 2 × 13 = 26.

Q 4 - The greatest common factor of 85 and 136 is

A - 13

B - 17

C - 34

D - 19

### Explanation

Step 1:

The prime factorization of 85 is

85 = 5 × 17

The prime factorization of 136 is

136 = 2 × 2 × 2 × 17

Step 2:

The greatest common factor of 85 and 136 is therefore 17.

Q 5 - The greatest common factor of 64 and 120 is

A - 4

B - 5

C - 6

D - 8

### Explanation

Step 1:

The prime factorization of 64 is

64 = 2 × 2 × 2 × 2 × 2 × 2

The prime factorization of 120 is

120 = 2 × 2 × 2 × 3 × 5

Step 2:

The greatest common factor of 64 and 120 is therefore 8.

Q 6 - The greatest common factor of 56 and 72 is

A - 8

B - 9

C - 12

D - 18

### Explanation

Step 1:

The prime factorization of 56 is

56 = 2 × 2 × 2 × 7

The prime factorization of 72 is

72 = 2 × 2 × 2 × 3 × 3

Step 2:

The greatest common factor of 56 and 72 is therefore 8.

Q 7 - The greatest common factor of 65 and 117 is

A - 11

B - 12

C - 13

D - 15

### Explanation

Step 1:

The prime factorization of 65 is

65 = 5 × 13

The prime factorization of 117 is

117 = 3 × 3 × 13

Step 2:

The greatest common factor of 65 and 117 is therefore 13.

Q 8 - The greatest common factor of 81 and 243 is

A - 9

B - 12

C - 18

D - 27

### Explanation

Step 1:

The prime factorization of 81 is

81 = 3 × 3 × 3 × 3

The prime factorization of 216 is

216 = 2 × 2 × 2 × 3 × 3 × 3

Step 2:

The greatest common factor of 81 and 216 is therefore 27.

Q 9 - The greatest common factor of 75 and 180 is

A - 12

B - 15

C - 18

D - 25

### Explanation

Step 1:

The prime factorization of 75 is

75 = 3 × 5 × 5

The prime factorization of 180 is

180 = 2 × 2 × 3 × 3 × 5

Step 2:

The greatest common factor of 75 and 180 is therefore 15.

Q 10 - The greatest common factor of 36 and 150 is

A - 6

B - 9

C - 12

D - 18

### Explanation

Step 1:

The prime factorization of 36 is

36 = 2 × 2 × 3 × 3

The prime factorization of 150 is

150 = 2 × 3 × 5 × 5

Step 2:

The greatest common factor of 36 and 150 is therefore 6.

greatest_common_factor_of_2_numbers.htm