Sheet # 236 Critical Thinking

Name: _____________________ Date_____________

**A tree has white lights which blink 10 times per minute and green lights which blink 15 times per minute. If they blinked simultaneously at 10:00 a.m., how many times will they blink together in the next hour?
**

Answer for sheet # 236

White light blinks 10 times per minute. It means it blinks every 6 seconds.

Green light blinks 15 times per minutes. It means it blinks every 4 seconds.

To determine when they will blink together, you need to find the LCM. The LCM of 4 and 6 is 12.

It means they will blink together every 12 seconds. They will blink together 5 times in a minute.

In one hour, they will blink 60 minutes x 5 times/minute = 300 times

Answer: 300 times