You have 7 marbles that all appear to be the same, but one is heavier than the others. You have a scale (one with 2 sides where you can compare 2 objects) Your task: Find the heavy marble, but you can only use the scale 2 times!
A neighbor of DH's family asked me this on our most recent trip. When people hear that you are a math person they like to test you (or tell you how much they hate math) I passed the test. Did you?
Without thinking this through, measure three and three. If they are the same, the seventh is the high. If they aren't, measure two of the higher side marbles against each other. If they are the same, it's the one you didn't measure from the second batch. Otherwise you know. Is my nine year old BS in math still good? :-)
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