Prime Numbers & Factors Quiz

Question 1

What is a prime number?

Accepted Answer

A number with exactly two factors: 1 and itself

Answer

A number divisible by itself only

Answer

An odd number

Answer

A number greater than 10

Question 2

Which of these is NOT a prime number?

Accepted Answer

15

Answer

11

Answer

13

Answer

17

Question 3

What is the only even prime number?

Accepted Answer

2

Answer

1

Answer

4

Answer

6

Question 4

What are the prime factors of 12?

Accepted Answer

2 and 3

Answer

2, 3 and 4

Answer

1, 2, 3 and 4

Answer

3 and 4

Question 5

What is the HCF (Highest Common Factor) of 24 and 36?

Accepted Answer

12

Answer

4

Answer

6

Answer

8

Question 6

What is the LCM (Lowest Common Multiple) of 4 and 6?

Accepted Answer

12

Answer

2

Answer

18

Answer

24

Question 7

Express 30 as a product of prime factors.

Accepted Answer

2 × 3 × 5

Answer

2 × 15

Answer

3 × 10

Answer

5 × 6

Question 8

How many prime numbers are there between 1 and 20?

Accepted Answer

8

Answer

6

Answer

7

Answer

9

Question 9

What is the LCM of 3, 4 and 6?

Accepted Answer

12

Answer

6

Answer

18

Answer

24

Question 10

Is 97 a prime number?

Accepted Answer

Yes

Answer

No, it's divisible by 7

Answer

No, it's divisible by 11

Answer

No, it's divisible by 3

Question 11

What is the HCF of 15 and 25?

Accepted Answer

5

Answer

3

Answer

10

Answer

15

Question 12

Write 72 as a product of its prime factors in index form.

Accepted Answer

2³ × 3²

Answer

8 × 9

Answer

2⁴ × 3

Answer

4 × 18

Question 13

What is a composite number?

Accepted Answer

A number with more than two factors

Answer

A number made by adding two primes

Answer

A very large number

Answer

A number divisible by 10

Question 14

Find the LCM of 8 and 12.

Accepted Answer

24

Answer

4

Answer

16

Answer

96

Question 15

What are twin primes?

Accepted Answer

Pairs of primes that differ by 2

Answer

Primes that are both even

Answer

Two consecutive prime numbers

Answer

Primes that double each other

Question 16

What is the HCF of 42 and 70?

Accepted Answer

14

Answer

7

Answer

10

Answer

21

Question 17

Is 1 a prime number?

Accepted Answer

No, it has only one factor

Answer

Yes, it only divides by 1

Answer

Yes, it is the smallest prime

Answer

No, it is a composite number

Question 18

What is the prime factorisation of 100?

Accepted Answer

2² × 5²

Answer

2 × 50

Answer

4 × 25

Answer

10²

Question 19

What is the smallest prime number greater than 50?

Accepted Answer

53

Answer

51

Answer

52

Answer

57

Question 20

Use the HCF of 18 and 30 to simplify the fraction 18/30.

Accepted Answer

3/5

Answer

6/10

Answer

9/15

Answer

2/3