Math CentralQuandaries & Queries


Question from Roselyn, a student:

Jenny and Mark commute to work, travelling in opposite directions. Jenny leaves the house at 8 AM, and averages 35 kph. Mark leaves at 8:15 AM, and averages 40 kph.At what time will they be 40 kilometers apart?

Hi Roselyn,

Jenny travels at 35 km/hr for 15 minutes before Mark leaves. 15 minutes is a quarter of an hour so how far apart are they at 8:15? How much further do they have to go before they are 40 kilometers apart?

After 8:15 how rapidly is the distance between them changing? At that rate how much time is needed until they are 40 kilometers apart?

Check your answer,

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