Prime and Composite Numbers Quiz

What is a prime number?

• A number with only two factors: 1 and itself

• A number with more than two factors

• A number that is even

• A number that is odd

Answer explanation

A prime number is defined as a number that has exactly two distinct positive factors: 1 and itself. This means it cannot be divided evenly by any other numbers, making the first choice the correct answer.

What is a composite number?

• A number with only two factors

• A number with more than two factors

• A number that is odd

• A number that is prime

Answer explanation

A composite number is defined as a number that has more than two factors. Unlike prime numbers, which have exactly two factors (1 and themselves), composite numbers can be divided by additional numbers.

Which of the following numbers is prime?

• 17

• 64

• 40

• 54

Answer explanation

17 is a prime number because it has no divisors other than 1 and itself. In contrast, 64 (2^6), 40 (2^3 * 5), and 54 (2 * 3^3) are composite numbers with multiple divisors.

Which of the following numbers is composite?

• 23

• 13

• 64

• 29

Answer explanation

A composite number has more than two distinct positive divisors. Among the choices, 64 is composite because it can be divided by 1, 2, 4, 8, 16, 32, and 64. The other numbers (23, 13, 29) are prime.

What are the factor pairs of 64?

• 8 and 8, 2 and 32

• 4 and 16, 2 and 32

• 5 and 13, 3 and 21

• 6 and 10, 2 and 30

Answer explanation

The factor pairs of 64 are combinations of numbers that multiply to give 64. The correct pairs are 8 and 8 (8x8=64) and 2 and 32 (2x32=64). Other options do not yield 64 when multiplied.

Which number is a prime number?

• 21

• 37

• 40

• 54

Answer explanation

A prime number is a natural number greater than 1 that has no positive divisors other than 1 and itself. Among the choices, 37 is prime, while 21 (3x7), 40 (5x8), and 54 (2x27) are not.

Which number is a composite number?

• 29

• 47

• 24

• 23

Answer explanation

A composite number has more than two distinct positive divisors. 24 is composite because it can be divided by 1, 2, 3, 4, 6, 8, 12, and 24. In contrast, 29, 47, and 23 are prime numbers.

What are the factor pairs of 40?

• 5 and 8, 4 and 10

• 6 and 7, 3 and 14

• 2 and 20, 3 and 13

• 1 and 40, 2 and 19

Answer explanation

The factor pairs of 40 are combinations of numbers that multiply to give 40. The correct pairs are 5 and 8, and 4 and 10, as both pairs multiply to 40. The other options do not yield 40 when multiplied.

Which of the following numbers is prime?

• 54

• 63

• 13

• 21

Answer explanation

A prime number is greater than 1 and has no positive divisors other than 1 and itself. Among the choices, 13 is prime, while 54, 63, and 21 are not, as they can be divided by numbers other than 1 and themselves.

Which of the following numbers is composite?

• 23

• 29

• 54

• 37

Answer explanation

A composite number has more than two distinct positive divisors. Among the choices, 54 is composite (divisors: 1, 2, 3, 6, 9, 18, 27, 54), while 23, 29, and 37 are prime numbers.