Quandaries and Queries

Name: Jane

Who is asking: Student
Level: Secondary

I have a question that involves writing an algebraic equation that involves distance/speed/time. I'm unable to figure this question out:

"Crystal drove from Sarnia at 80km/hr. Emily left Sarnia one hour later and drove along the same road at 100km/hr. How far from Sarnia did Emily overtake Crystal?"

Thank you.

Hi Jane,

First, ask yourself "how long did Emily take to catch up with Crystal?"

Call T this time. The distance traveled by Emily in this time is

T * (100 km/h), (distance = time * speed) and it should be the same as the distance traveled by Crystal, which is (T + 1) * (80 km/h) (because she left 1 hour early). Solving this equation will give you T, from which you should deduce the distance.


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