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?
Since only a few laps are involved, you can simply add up the times. The second lap will take 50*1.2 = 60 seconds. The third lap will take 60*1.2 = 72 seconds.
The total time for 3 laps will be (50 +60 +72) seconds = 182 seconds.
