3.4 and 3.5 Test Prep (Prime Factorization and LCM

A radio station is giving away a $100 bill to every 30th caller and movie tickets to every 40th caller.  Which caller will be the first to win both prizes?

• 5
• 2
• 10
• 120

Two neon signs are turned on at the same instant and begin to blink. One sign blinks every 9 seconds. The other blinks every 15 seconds. In how many seconds will they blink together?

• 3

• 5

• 45

• 9

The school cafeteria serves tacos every sixth school day and cheeseburgers every eighth school day. If tacos and cheeseburgers are both on today's menu, in how many school days will they both be on the menu again?

• 24

• 2

• 6

• 12

Two clocks are started at 2:00 pm. One chimes every 15 minutes. The other chimes every 25 minutes. At what time will they chime together?

• 3:45 pm

• 3:15 pm

• 3:25 pm

• 3:15 pm

Coach Sara and Coach Sarina are both building a toy train track out of connecting pieces. Coach Sara has pieces that are 8 inches long, while Coach Sarina's pieces are 20 inches long. How long will the shortest track be that they can each build with equal lengths?

• 160 inches

• 40 inches

• 80 inches

• 3 feet 2 inches

Colette and Lin are traveling around a circular track. Colette is using her wheelchair and takes 7 minutes to make one loop. Lin is walking and takes 12 minutes to make one loop. If they begin at the starting line at 3:50 pm, at what time will they meet each other at the starting line again?

• 4:14 pm

• 4:34 pm

• 5:14 pm

• 5:04 pm

A red subway arrives at the station every 18 minutes. A blue subway comes every 27 minutes. If they are both arrive at the station now, how long will it be until they are both at the station again?

• 486

• 450

• 45

• 54

What is the LCM of 6 and 9?

• 3

• 18

• 30

• 36

What is the LCM of 2, 4, 6?

• 6
• 12
• 4
• 2

Every sixth visitor to an animal shelter gets a free animal calendar. Every twentieth visitor gets a free animal toy. Which visitor each day will be the second one to get both the calendar and the animal toy?

• Visitor 20

• Visitor 26

• Visitor 120

• Visitor 60