you could cash in 21 cards in one turn in...the most you could have at 1 time would be 25 ( but you couldn't turn in)
green has 5 cards
yellow has 4
blue has 4
red has 4
aqua has 4
purple has 4
yellow takes out green yellow has 9
blue takes out yellow, blue has 13
red takes out blue, red has 17 ...