Sheila went to a street market where she bought 20 tulips (x) and 4 roses (y). Bruce also went to a market where he bought 18 tulips (x) and 9 roses (y).

1. a)If Sheila and Bruce went to the same market and paid the same prices, then can they find a mutually beneficial trade? If so then who will give up tulips? Briefly explain.
2. b)If they went to different markets and faced different prices, then can they find a mutually beneficial trade of tulips and roses? If so then who will give up tulips? Briefly explain.