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A Problem From an Article on Arithmetic Anxiety

A train leaves Colorado Springs at 9 a.m. bound for Boulder, Colorado, 100 miles away. It travels at 50 mph and has to pick up passengers every 25 miles. Each stop takes 10 minutes, and after each stop, the increased passenger weight causes the train's speed to decrease by 10 percent. When will the train arrive?

  • About 11:52 a.m.
  • About 11:22 a.m.
  • I would rather throw myself in front of that train than figure out when it's going to arrive. Why do I need to know this stuff anyway? Smart people just look at the freakin' train schedule.


Source: http://news.bellinghamherald.com/apps/pbcs.dll/article?AID=/20060926/NEWS04/609260315/1006/LIFE

Hint: Can you just stop and think about the problem...visualize its actions?

You do not need algebra...or a complicated equation!


Solution Commentary: If the train was not slowing doen by 10% each time, how long would it take the train to travel the 100 miles...be sure to include the 3 stops at 10 minutes each? So its arrival time would be....?

Now, is the train going to go slower or faster than this scenario? That is, will it arrive at 11:52 am or 11:52 am?