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Jenna and Nina are running laps around the outside of their house. They both start at the front door at the same time.
Jenna takes 18 seconds to run all the way around. Nina takes 20 seconds. If they maintain the same speed,
how long will it be before they are both at the front door at the same time again?
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When Nina will complete her 9-th loop (180 seconds), Jenna will complete her 10-th loop,
and they both will be at the front door at the same time.
Answer. 180 seconds.
Thank you for submitting such a brilliant problem.