Platonic Perplexer: Cubes

I remember as a kid seeing puzzles in Highlights Magazine where you had to spot the differences between two pictures.  These puzzles are kind of the opposite of that, since you're trying to spot the two objects that are the same.  The twist is that the objects have been rotated ahead of time.

Any cube with three red, three white, and two orange corners can be rotated into exactly one of twenty-four distinct configurations.  Here, each group has twenty-five cubes, telling us that at least two are really the same after some rotation.  For the following three sets of cubes, each has only one such pair, and your objective is to find it.

Solution
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