Prime and Composite Numbers Worksheet

**Page 1**

1.

Say whether the number 14 is prime or composite.

a. | composite | ||

b. | prime |

The number 14 can be factorized as 1 × 14 and 2 × 7.

Its factors are 1, 2, 7, and 14.

The number 14 has more than two factors showing more than one rectangular array.

So, the number 14 is composite.

Correct answer : (1)

2.

Which of the following is not a composite number?

a. | 17 | ||

b. | 12 | ||

c. | 26 | ||

d. | 22 |

Factors of 26: 1, 2, 13 and 26

Factors of 22: 1, 2, 11 and 22

Factors of 17: 1 and 17

Factors of 12: 1, 2, 3, 4, 6, 12

The number 17 has exactly 2 factors, 1 and 17.

So, the number 17 is not a composite number.

Correct answer : (1)

3.

Identify the composite number.

a. | 113 | ||

b. | 59 | ||

c. | 71 | ||

d. | 20 |

Factors of 59 = 1, 59

Factors of 71 = 1, 71

Factors of 113 = 1, 113

Factors of 20 = 1, 2, 4, 5, 10, 20.

Out of the given numbers, 20 is the only number that has more than two factors.

So, 20 is the composite number.

Correct answer : (4)

4.

Identify the composite number.

a. | 47 | ||

b. | 53 | ||

c. | 31 | ||

d. | 32 |

Factors of 31 = 1, 31

Factors of 53 = 1, 53

Factors of 47 = 1, 47

Factors of 32 = 1, 2, 4, 8,16, 32

Out of the given numbers, 32 is the only number that has more than two factors.

So, 32 is the composite number.

Correct answer : (4)

5.

Identify the composite number.

a. | 36 | ||

b. | 47 | ||

c. | 13 | ||

d. | 23 |

Factors of 23 = 1, 23

Factors of 13 = 1, 13

Factors of 47 = 1, 47

Factors of 36 = 1, 2, 3, 4, 6, 9, 12, 18, 36

Out of the given numbers, 36 is the only number that has more than two factors.

So, 36 is the composite number.

Correct answer : (1)

6.

Identify the composite number.

a. | 37 | ||

b. | 29 | ||

c. | 44 | ||

d. | 17 |

other than 1 and itself.

In the given choices, 37, 17, and 29 are prime numbers.

44 has factors 1, 2, 4, 11, 22, and 44.

Thus, 44 has factors other than 1 and 44.

So, 44 is a composite number.

Correct answer : (3)

7.

Which of these is a composite number?

a. | 13 | ||

b. | 41 | ||

c. | 45 | ||

d. | 37 |

In the given choices, 13, 41, and 37 are prime numbers.

45 has factors 1, 3, 5, 9 15, and 45.

Thus, 45 has factors other than 1 and 45.

So, 45 is a composite number.

Correct answer : (3)

8.

Identify the prime number.

a. | 9 | ||

b. | 29 | ||

c. | 52 | ||

d. | 34 |

In the given choices, 9, 34, and 52 have factors other than 1 and itself.

Factors of 29 are 1 and 29.

So, 29 is a prime number.

Correct answer : (2)

9.

List all the prime numbers greater than 30 and less than 40.

a. | 31 and 37 | ||

b. | 31, 37, and 39 | ||

c. | 23 and 27 | ||

d. | 17 and 19 |

List of prime numbers greater than 30 and less than 40 are 31 and 37.

Correct answer : (1)

10.

Which of these is not a prime number?

a. | 2 | ||

b. | 14 | ||

c. | 13 | ||

d. | 17 |

Factors of 17 : 1 and 17

Factors of 13 : 1 and 13

Factors of 2 : 1 and 2

Factors of 14 : 1, 2, 7, 14

The number 14 has more than 2 factors.

So, the number 14 is not a prime number.

Correct answer : (2)