Prime Numbers Online Quiz



Following quiz provides Multiple Choice Questions (MCQs) related to Prime 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.

Questions and Answers

Q 1 - Which one of the following numbers is a prime number?

A - 0

B - 1

C - 2

D - 4

Answer : C

Explanation

Step 1:

0 is neither prime nor composite.

1 is neither prime nor composite.

4 has factors 1, 2 and 4. It is composite.

Step 2:

Only 2 among the given numbers is a prime number as it is only divisible by 1 and itself.

Q 2 - Which one of the following numbers is a prime number?

A - 3

B - 4

C - 6

D - 8

Answer : A

Explanation

Step 1:

4 has factors 1, 2, and 4. It is composite.

6 has factors 1, 2, 3, and 6. It is composite.

8 has factors 1, 2, 4, and 8. It is composite.

Step 2:

Only 3 among the given numbers is a prime number as it is only divisible by 1 and itself.

Q 3 - Which one of the following numbers is a prime number?

A - 14

B - 15

C - 18

D - 19

Answer : D

Explanation

Step 1:

14 has factors 1, 2, 7 and 14. It is composite.

15 has factors 1, 3, 5, and 15. It is composite.

18 has factors 1, 2, 3, 6, 9 and 18. It is composite.

Step 2:

Only 19 among the given numbers is a prime number as it is only divisible by 1 and itself.

Q 4 - Which one of the following numbers is a prime number?

A - 6

B - 7

C - 8

D - 9

Answer : B

Explanation

Step 1:

6 has factors 1, 2, 3, and 6. It is composite.

8 has factors 1, 2, 4, and 8. It is composite.

9 has factors 1, 3, and 9. It is composite.

Step 2:

Only 7 among the given numbers is a prime number as it is only divisible by 1 and itself.

Q 5 - Which one of the following numbers is a prime number?

A - 18

B - 21

C - 23

D - 24

Answer : C

Explanation

Step 1:

18 has factors 1, 2, 3, 6, 9 and 18. It is composite.

21 has factors 1, 3, 7, and 21. It is composite.

24 has factors 1, 2, 3, 4, 6, 8, 12 and 24. It is composite.

Step 2:

Only 23 among the given numbers is a prime number as it is only divisible by 1 and itself.

Q 6 - Which one of the following numbers is NOT a prime number?

A - 11

B - 13

C - 15

D - 17

Answer : C

Explanation

Step 1:

11 has factors 1 and 11. It is prime.

13 has factors 1 and 13. It is prime.

17 has factors 1 and 17. It is prime.

Step 2:

Only 15 is NOT a prime number as it has three or more factors like 1, 3, 5, 15.

Q 7 - Which one of the following numbers is NOT a prime number?

A - 28

B - 29

C - 31

D - 37

Answer : A

Explanation

Step 1:

29 has factors 1 and 29. It is prime.

31 has factors 1 and 31. It is prime.

37 has factors 1 and 37. It is prime.

Step 2:

Only 28 is NOT a prime number as it has three or more factors like 1, 2, 4, 7, 14, and 28.

Q 8 - Which one of the following numbers is NOT a prime number?

A - 41

B - 43

C - 47

D - 49

Answer : D

Explanation

Step 1:

41 has factors 1 and 41. It is prime.

43 has factors 1 and 43. It is prime.

47 has factors 1 and 47. It is prime.

Step 2:

Only 49 is NOT a prime number as it has three factors like 1, 7 and 49.

Q 9 - Which one of the following numbers is NOT a prime number?

A - 53

B - 57

C - 59

D - 61

Answer : B

Explanation

Step 1:

53 has factors 1 and 53. It is prime.

59 has factors 1 and 59. It is prime.

61 has factors 1 and 61. It is prime.

Step 2:

Only 57 is NOT a prime number as it has three or more factors like 1, 3, 19 and 57.

Q 10 - Which one of the following numbers is NOT a prime number?

A - 67

B - 71

C - 72

D - 73

Answer : C

Explanation

Step 1:

67 has factors 1 and 67. It is prime.

71 has factors 1 and 71. It is prime.

73 has factors 1 and 73. It is prime.

Step 2:

Only 72 is NOT a prime number as it has three or more factors like 1, 2, 3, 4, 6, 8, 9, 12, 18, 24, 36 and 72.


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