Einstein Brain Teaser

Coudal Partners
Brain teaser allegedly from Einstein. Three randomly selected people who get it right by Monday the 8th will win a limited edition disc set of the Pixies at Lollapolooza and a few other things of lesser importance. I've figured it out. If you comment that you want hints, I might oblige. Anyone who wants to submit an entry and give me the Pixies part of the prize can have the answer, no muss no fuss.