Review Prime factorization

Kelsey has 6 blue marbles and 9 white ones. If she wants to place them in identical groups without any marbles left over, what is the greatest number of groups Kelsey can make?

• 6

• 9

• 3

• 54

A family is preparing backpacks filled with school supplies to donate to children in need. They have 10 pencils and 20 notebooks. If they want to make all the backpacks the same, with no school supplies left over, what is the greatest number of backpacks they can fill?

• 12

• 10

• 20

• 30

Elizabeth's Sweets sells donuts in packages of 10. Across town, Madison Pastries sells donuts in packages of 5. If Heather wants to buy the same number of donuts from each bakery for a taste test, what is the smallest number of donuts she will have to buy from each?

• 10

• 15

• 50

• 5

Find the highest common factor and least common multiple of 576 and 1440

• 300 and 3490

• 57 and 1000

• 288 and 2880

• 450 and 2880

Find the GCF of 20, 30 and 50

• 10

• 20

• 15

• 25

Find the GCF of 32, 48, 40

• 4

• 8

• 6

• 10

Find the LCM of 32, 40, 16

• 100

• 150

• 160

• 170

Find the LCM of 24, 32, 16

• 96

• 150

• 69

• 240

Pencils come in packages of 10. Erasers come in packages of 12. Phillip wants to purchase the smallest number of pencils and erasers so that he will have exactly 1 eraser per pencil. How many packages of pencils and erasers should Phillip buy?

• 4 packages of pencils and 3 packages of erasers

• 5 packages of pencils and 4 packages of erasers

• 6 packages of pencils and 5 packages of erasers

• 12 packages of pencils and 10 packages of erasers

Beginning at 8:30 A.M., tours of the National Capitol and the White House begin at a tour agency. Tours for the National Capitol leave every 15 minutes. Tours for the White House leave every 20 minutes. How often do the tours leave at the same time?

• Every 15 minutes

• Every 30 minutes

• Every 45 minutes

• Every 60 minutes