Word Problems

Interesection

20. One sign flashes every 4 seconds, and another sign flashes every 14 seconds. At a certain instant, the 2 signs flash at the same time. How many seconds elapse until the 2 signs next flash at the same time?
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Least Common Multiple (LCM)

2013 June(71C) Math Question 20

22. Two warning signs begin flashing at the same time. One sign flashes every 3 seconds, and the other sign flashes every 8 seconds. How many seconds elapse from the moment the 2 signs flash at the same time until they next flash at the same time?

2021 April(D05) Math Question 22

25. One caution sign flashes every 4 seconds, and another caution sign flashes every 10 seconds. At a certain instant, the 2 signs flash at the same time. How many seconds elapse until the 2 signs next flash at the same time?

InteresectionWord ProblemsACT math questions

2013 June(71C) Math Question 20

2021 April(D05) Math Question 22