LCM AND GCF PRACTICE PROBLEMS WORKSHEET

Problem 1 :

The greatest common factor (GCF) of 24 and 72 is ____.

A. 3      B. 13      C. 23     D. 24

Solution

Problem 2 :

Find the set of numbers which has the GCF and LCM for the set.

A. 9, 21, 32, 41       B. 5, 15, 17, 19

C. 7, 21, 42             D. 4, 13, 15, 18

Solution

Problem 3 :

The LCM of 8, 12, and 24 is _____.

A. 36      B. 28    C. 26       D. 24

Solution

Problem 4 :

Allan wants to cut a 60 cm long and 90 cm long stick into the same length for his project. What is the length of that piece of sticks ?

A. 20 cm       B. 30 cm    C. 40 cm     D. 50 cm

Solution

Problem 5 :

The greatest common factor of 18 and 12 is _____.

A. 12      B. 18      C. 6      D. 9

Solution

Problem 6 :

If the LCM of a set of number is 24. What are the numbers ?

A. 7 and 8        B. 6 and 9       C. 3 and 6     D. 4 and 5

Solution

Problem 7 :

The LCM of 9 and 6 is _____.

A. 36       B. 18      C. 42     D. 21

Solution

Problem 8 :

The GCF of 24 and 36 is _____.

A. 12       B. 8     C. 6       D. 4

Solution

Problem 9 :

What is the LCM of 12, 7, and 3 ?

A. 273        B. 252        C. 127             D. 84

Solution

Problem 10 :

What pair of numbers between 110 and 140 have 17 as their GCF ?

Solution

A. Use the continuous division to find the GCF of each pair of numbers.

Problem 11 :

The GCF of 12 and 20 = _____

Solution

Problem 12 :

The GCF of 20 and 35 = _____

Solution

Problem 13 :

15 and 9

GCF = _____

Solution

Problem 14 :

8 and 40

GCF = _____

Solution

Problem 15 :

16 and 48

GCF = _____

Solution

Write all the factors of the set of numbers and find the GCF.

Problem 16 :

28 and 48

28 : _____

48 : _____

GCF : _____

Solution

Problem 17 :

16 and 32

16 : _____

32 : _____

GCF : _____

Solution

Problem 18 :

8 and 12

8 : _____

12 : _____

GCF : _____

Solution

Problem 19 :

8, 12 and 16

8 : _____

12 : _____

16 : _____

GCF : _____

Solution

Problem 20 :

6, 24 and 36

6 : _____

24 : _____

36 : _____

GCF : _____

Solution

Answer Key

1)  24, option D

2) 42, option C

3)  24, option D.

4)  30 cm. Option B.

5)  6, option C

6)  24, option C

7) 18, option C

8)  12, option A

9)  84, option D

10) 17, option B.

11)  

GCF = 4

12)  

GCF = 5

13)  GCF = 3

14)  GCF = 8

15)  GCF = 16

16)   the greatest common factor (GCF) of 28 and 48 is 4.

17)  the greatest common factor (GCF) of 16 and 32 is 16.

18)  the greatest common factor (GCF) of 8 and 12 is 4.

19)  (GCF) of 8, 12 and 16 is 4.

20)  (GCF) of 6, 24 and 36 is 6.