Choose GCF or LCM to solve a problem

Question 1

Two runners start together on a track. One completes a lap every 14 seconds, the other every 21 seconds. After how many seconds will they next be together?

Answer 

Question 2

A club has 66 red tulips and 77 yellow tulips. They make identical kits with nothing left over. What is the greatest number of kits they can make?

Answer 

Question 3

Which do you need: the GCF or the LCM? Buy packs of plates and packs of cups so you have the same number of each.

• A. GCF
• B. LCM

Question 4

Two buses leave the station together. One leaves every 9 minutes and the other every 12 minutes. After how many minutes will they next be together?

Answer 

Question 5

A club has 33 stickers and 22 badges. They make identical kits with nothing left over. What is the greatest number of kits they can make?

Answer 

Question 6

Which do you need: the GCF or the LCM? Cut two ribbons into equal pieces that are as long as possible.

• A. GCF
• B. LCM

Question 7

Two lighthouse lights flash together. One flashes every 14 seconds, the other every 21 seconds. After how many seconds will they next be together?

Answer 

Question 8

A club has 20 apples and 28 oranges. They make identical kits with nothing left over. What is the greatest number of kits they can make?

Answer 

Question 9

Which do you need: the GCF or the LCM? Find when two blinking lights next blink at the same time.

• A. GCF
• B. LCM

Question 10

Two buses leave the station together. One leaves every 10 minutes and the other every 15 minutes. After how many minutes will they next be together?

Answer 

Question 11

A club has 36 red tulips and 30 yellow tulips. They make identical kits with nothing left over. What is the greatest number of kits they can make?

Answer 

Question 12

Which do you need: the GCF or the LCM? Find when two blinking lights next blink at the same time.

• A. GCF
• B. LCM

Question 13

Two runners start together on a track. One completes a lap every 10 seconds, the other every 15 seconds. After how many seconds will they next be together?

Answer 

Question 14

A club has 42 red tulips and 49 yellow tulips. They make identical kits with nothing left over. What is the greatest number of kits they can make?

Answer 

Question 15

Which do you need: the GCF or the LCM? Cut two ribbons into equal pieces that are as long as possible.

• A. GCF
• B. LCM

Question 16

Two buses leave the station together. One leaves every 20 minutes and the other every 30 minutes. After how many minutes will they next be together?

Answer