Archived Stumpers (with solutions)
Stumper #1.1: RIVER RIDDLES
(Did you solve something differently? There's almost always more than one way to solve
a math problem. Sometimes there's even more than one correct solution!)
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3. Measuring Up
You are standing by a river bank when a passing traveler offers you a rich reward if you can give him exactly 1 cup of water from the river. You have only a 3-cup container and a 5-cup container. What do you do?
Here's one way to do it. Fill up the 3-cup container, and then pour all the water from it into the 5-cup container. Fill up the 3-cup container again, and pour as much as will fit into the 5-cup container. Only two cups will fit, since there were already three inside. You’ll be left with exactly one cup in the 3-cup container.