hi, missing part A and part B.... for part B needs also shortage and surplus plus the underlying blank hope you can help

Price Quantity demanded Quantity supplied $10 100 400 8 150 350 6 250 250 4 275 200 2 300 200 a) What is the most efcient price AND quantity (i.e. the market/equilibrium price and quantity)? b) If the price was $8, then the quantity supplied would be and quantity demanded would be , leading to a ( shortage surplus ) of units