Goof: When Ross arrived at Monica and Chandler's apartment just before the lotto drawing, the friends were surprised to see him. Monica said since he was there, she wanted him to participate in their lotto ticket pool, so she would put in $50 for him (and Ross then said he'd pay for the tickets himself). Since no one (including Monica) knew Ross would be there for the drawing, how did Monica know to get 50 extra tickets when she was in Connecticut? And why didn't this alert everyone else to the fact that Monica bought many more tickets than the agreed upon number?
Note: When Monica is explaining how they will sort through the tickets to see if they've won, she says they'll divide up the tickets into 6 groups of 40 and whoever finishes first can go through the other 10. In other words, they only have 250 tickets. Obviously, Ross's contribution would be divided between the others so that everyone paid equally for their share of the 250 tickets. The only inconsistency is when Monica says that she'll throw in $50 for Ross, since his contribution with only 250 tickets would be about $42.