Yeah, I noticed that, too. I was like.... wait, n^2 = n?????? WTF? Which n do they want? But yeah, Stacey has it right. The first n would be 1000, and the second n would be 1,000,000 (one million). Root - your logic is correct, but you messed up a bit on your math. 1999/2 + 0.5 = 1000, not 500. Anyway, you guys are basically doing the same thing, just in a different order. Stacy's method is probably a bit easier, but they both work out the same way.