Which pairs of pairs of rationals have the property that the sum of the cubes of one pair equals the sum of the cubes of the other pair? —Dan ----- The pump stopped > $3 short of the $20 I gave the Desi clerk, so I squeezed it up to $17 and, remembering that a new employee at Empress of India had once accepted one, demanded a $3 bill with Bill Clinton's picture on it. The clerk said $2.71. In disbelief, I walked back to the pump. It said $17.29. The clerk denied that 1729 meant anything to him, but became very enthusiastic when I mentioned Ramanujan. I still don't understand where that 29¢ came from. There now was actually a little gas spilled on the ground. -----