Question 1123968
A yellow neon light blinks every 6 seconds, a pink neon light blinks every 5 seconds,and a red neon light blinks every 4 second. How many times within 30 minutes will they blink together.?
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The LCM = 60 seconds --> coincident once per minute.
30 minutes --> 30 coincident blinks,
OR 31 if it's from zero to 30 inclusive.