Question

A long distance runner does a first lap around a track in exactly 50 seconds. As she tires each subsequent lap takes 20% longer than the previous one. How long does she take to run 3 laps?

Answer 1

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Answer:

182 seconds, or 3 minutes 2 seconds

Explanation:

The second lap takes ...

(50 s)(1 +20%) = (50 s)(1.2) = 60 s

The third lap takes ...

(60 s)(1.2) = 72 s

The three laps take 50 +60 +72 = 182 seconds, or 3 minutes 2 seconds.