Wednesday, June 19, 2013

Wednesday Brain Teaser 6-19-13

I think my one last week was too hard.  I'll provide the answer as soon as I can find it...I'm trying to remember which book I got it out of.

Anyway, here's an easier one:

A car travels at a speed of 50 mph over a certain distance, and then goes 30 mph over the same distance on the way back.  What's the average speed for the trip?

3 comments:

  1. I'm getting 37.5 miles per hour...

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  2. The answer to last week's puzzle:

    3+(69258/714)
    81+(5643/297)
    81+(7524/396)
    82+(3546/197)
    91+(5742/638)
    91+(5823/647)
    91+(7524/836)
    94+(1578/263)
    96+(1428/357)
    96+(1752/438)
    96+(2148/537)

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  3. Last week's didn't seem so much hard as tedious. I would have bit for a version that said "There are ten solutions. Nine start with a whole number greater than 80. Which one doesn't?"

    As for today's, as the answer is the same for any distance, you can just pick one. I pick 50 miles, which results in traveling 100 miles in 2 hours and 40 minutes, which does indeed equal 37.5mph. The initial impulse is to just guess 40. But it's a puzzle, so you know that's going to be wrong...

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