A jet left Nairobi and flew east at an average speed of 231 mph. A passenger plane left four hours l

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A jet left Nairobi and flew east at an average speed of 231 mph. A passenger plane left four hours later and flew in the same direction but with an average speed of 385 mph. How long did the jet fly before the passenger plane caught up?

Jet distance = 231t
Passenger plane distance = 385(t - 4)

385(t - 4) = 231t
385t - 1540 = 231t

Subtract 231t from each side
154t = 1540

Type 154t = 1540 into the search engine, we get t = 10.

Check our work:
Jet distance = 231(10) = 2,310
Passenger plane distance = 385(10 - 4) = 385 * 6 = 2,310