Correct solutions were also received from Carli Guyon, Sean Koors, Kristian Chelstrom, Christopher LaGatta.  Further correct solutions were submitted by Aaron Kahn, Al Zimmermann, Brian Laughlin, Ahmed Aboadham, Nancy Schwarzkopf, Burkart Venzke, John Stamper, Bill Webb, Scott Powell, Johann Moll, Ritwik Chaudhuri, Dane Brooke, Iñigo Picaza, Mark Warren, Lou Cairoli, Paul Botham, Steve Prowse, Francesc Suñol y Esquirol, Philippe Fondanaiche, A. Teitelman, Sudipta Das, Ron Welch, Selina Giles, .

If the first student sees two white hats, he would know taht he was wearing a red hat.  If he sees any other combination, he does not know the color of his own hat.  Therefore the second and third students are not both wearing white hats.   Knowing this, if the second student sees a white hat on the third student, she would know that her own hat had to be red.  Since the second student does not know her own hat color, the third student's hat must be red!

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