I need help regarding this question this question is from 2019 Indonesian National Science Olympiade for Mathematics Teacher. The question is ...
Johnny and Diego are jogging on a circular track. Both start running at the same point. Johnny run with the speed of 50 km/h while Diego run with the speed of 80 km/h. after completing a lap, DIego rests for 30 minutes. After that he run again, and he meets Johnny. How long is the circumference of the track?
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Top NewestI got the answer as 3200 m. Here is my solution :
Let the circumference of the track be x. Also, lets assume that Diego takes time t (in hours) to completer one lap. It is given that he takes 0.5 hours rest and then meets Johny. From this we can conclude that Johny takes t+0.5 hours to complete the lap. We know their speeds so put them in the condition x=v⋅t where, v is their respective speeds.
x=80⋅tx=50⋅(t+0.5) On solving we get t=65 hr=50 min and x=3200 km.
(But I can't imagine a track which has circumference almost equal to 67 Km)
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Thank you.
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But is my answer correct.
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I find the wording "After that he runs again, and he meets Johnny" confusing, but if it just means that Johnny finishes 30 minutes later than Diego then I get an answer of 200/3 km as well. This is an unusually long track, (10.61 km radius), and the speeds of the two runners is beyond what humans are capable of (without superpowers).
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