Review; Factors, multiples LCM & GCF

GED Review;
Skill 2 - Multiples & Common Factors

By the end of this lesson, you should be able to;
List factors of a number,
Find the Greatest common factor (GCF of two or more numbers)
Find the Least common multiple of two or more number

Multiple Choice

Which are the factors of 14?

• 1 x 14

• 1x 14, 2 x 7

• 2 x 7

Multiple Choice

Which are the factors of 24?

• 1,x 24, 2 x 12, 3 x 8

• 2 x 12

• 1 x 24

Multiple Choice

Which lists all of the factors of 18?

• 1, 2, 3, 5, 6, 9, 18
• 1, 3, 6, 18
• 1, 2,  9, 18
• 1, 2, 3, 6, 9, 18

Multiple Choice

Which of these is a NOT a factor of 30?

• 2

• 3

• 5

• 7

Multiple Choice

Which of these is a NOT a factor of 24?

• 2

• 3

• 5

Multiple Choice

Which number is a multiple of 3?

• 27
• 28
• 29
• 26

Multiple Choice

Which number is a multiple of 5?

• 73
• 74
• 75
• 76

Multiple Choice

Which number is a multiple of 5?

• 1,000
• 1,001
• 1,002
• 1,003

Multiple Choice

Which number is NOT a multiple of 5

• 55
• 60
• 65
• 07

Multiple Choice

Which number is a multiple of 2?

• 55
• 53
• 54
• 25

Multiple Choice

What is the GCF of 18 and 24?

• 3

• 6

• 8

• 9

Multiple Choice

What is the GCF of 4 and 12?

• 3
• 1
• 6
• 4

Multiple Choice

What is the greatest factor of 28 and 49?

• 1
• 2
• 7
• 12

Multiple Choice

GCF of 36 and 99

• 9
• 6
• 11
• 4

Multiple Choice

GCF of 20 and 70

• 2
• 5
• 7
• 10

Multiple Choice

GCF of 28 and 40

• 2
• 4
• 7
• 8

Multiple Choice

GCF of 24 and 56

• 2
• 4
• 6
• 8

Multiple Choice

What is the LCM of 4 and 12? 

• 4
• 8
• 12
• 16

Multiple Choice

What is the LCM of 6 and 8 ?

• 12
• 18
• 24
• 36

Multiple Choice

What is the Least Common Multiple of 12 and 10?

• 22

• 44

• 110

• 120

Multiple Choice

What is the least common denominator of 1/7 and 2/12?

• 56

• 60

• 84

• 14

Multiple Choice

What is the LCM of 2, 4, 6?

• 6
• 12
• 4
• 2

Multiple Choice

The least common multiple of 12, 30, and 40 is…

• 40

• 60

• 120

• 160

Application problems

These problems are the kind of word / application problems on the GED.

Multiple Choice

Lamp A lights up every 15 minutes and lamp B lights up every 20 minutes. If at 09.00 the two lights turn on together, the second lamp will turn on together again for the second time at ...

• 09.30

• 09.45

• 10.00

• 10.30

Multiple Choice

Colton has 16 blue marbles and 8 white ones. If he wants to place them in identical groups without any marbles left over, what is the maximum amount of groups Colton can make?

Do I find the GCF or the LCM?

• GCF

• LCM

Multiple Choice

Two neon signs are turned on at the same time. Both signs blink as they are turned on. One sign blinks every 9 seconds. The other sign blinks every 15 seconds. In how many seconds will they blink together again?

Do I find the GCF or the LCM?

• GCF

• LCM

Multiple Choice

The school cafeteria serves tacos every sixth day and cheeseburgers every eight day. How many days will it be before they are both on the menu?

Do I find the GCF or the LCM?

• GCF

• LCM

Multiple Choice

Wilma is thinking of a number that is divisible by both 17 and 8. What is the smallest possible number that Wilma could be thinking of?

Do I find the GCF or the LCM?

• GCF

• LCM

Multiple Choice

I am planting 50 apple trees and 30 peach trees. I want the same number and type of trees per row. What is the greatest number of trees I can plant per row?

• 3

• 5

• 10

• 15

Multiple Choice

There are 20 girls and 32 boys who want to participate in 6th grade intramurals. If each team must have the same number of boys and girls, what is the maximum amount of teams participating?

• 4

• 5

• 8

• 10

Multiple Choice

Hannah is making a game board that is 16 inches by 24 inches. She wants to use square tiles. What is the largest tile size she can use?

• 6

• 8

• 12

• 16

Multiple Choice

Boxes that are 12 inches tall are being stacked next to boxes that are 8 inches tall. What is the shortest height at which the two stacks will be the same height?

• 8

• 12

• 16

• 24

Fill in the Blanks

What is the smallest number of plates Mr. Brian can buy?

Multiple Choice

If a wire is cut into pieces of 16 meters and 24 meters, what is the longest length that can be measured exactly?

• 20

• 8

• 10

• 12