SOLUTION: A passenger plane left Singapore and flew toward Jakarta. A jet left two hours later flying 140 km/h faster in an effort to catch up to it. After three hours the jet finally caught

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Question 1122466: A passenger plane left Singapore and flew toward Jakarta. A jet left two hours later flying 140 km/h faster in an effort to catch up to it. After three hours the jet finally caught up. Find the passenger plane's average speed.
Answer by greenestamps(13200) About Me  (Show Source):
You can put this solution on YOUR website!


The jet flies in 3 hours the same distance that the passenger plane flies in 5 hours; that means the ratio of the speeds of the two planes is 5:3.

Knowing that ratio, let the speed of the passenger plane be 3x and the speed of the jet be 5x.

The difference in speeds is 140 km/h:

5x-3x = 2x
2x = 140
x = 70

The speed of the passenger plane is 3x = 210 km/h; the speed of the jet is 5x = 350 km/h.