Help on these 3 questions!

Given inverse demand function P=34219Q, what does the price need to be so that sales ace Q=10 ? 18 36 152 171 QUESTION 4 A competitive (price taker) firm has cost function C=400+40Q+2Q2. At a market price of $100, how much output should this firm produce to maximize profin? 4 15 20 24 QUestion 5 A competitive firm hes cost function C=1,000+27.5Q+10Q2. At which quantity does the firm minimize its average cost? 10 55 100 500