Puzzler Answer 9626, Potato

Ray: Now we stated that potatoes are 99 percent water and 1 percent potato. So, say you take a bunch of potatoes, like 100 pounds of potatoes, and you set them out on your back porch to dry out. As they begin to dry out, the water starts to evaporate. And after awhile enough water has evaporated so that the potatoes are now 98 percent water. The question was very simple, if you were to weigh those potatoes at that moment when they are 98 percent water, how much would they weigh? Now, unencumbered by the thought process as usual, my brother guessed 99 pounds.

Tom: Yeah.

Ray: Now, when I guessed, off the top of my head, I guessed about 90 pounds.

Tom: 'Cause it just feels right.

Ray: Yeah. Now if you do the math, 1 percent of a 100, which is what the potato is, is one pound. As we told you, that's 1 percent. So 2 percent, when its 98 percent water, two percent of the new weight of the mass is still going to be equal to that one pound, and 2 percent of 50 pounds is a pound. So the potato weight is now 50 pounds, not 100.

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