(a) The profit function is $\pi(Q)=24 Q-Q^{2}-5$. Find the marginal profit, and find the value $2^{*}$ of $Q$ that maximizes profits. (b) The revenue function is $R(Q)=500 Q-\frac{1}{3} Q^{3}$. Find the marginal revenue. (c) Find marginal cost when $C(Q)=-Q^{3}+214.2 Q^{2}-7900 Q+320700$. (This particular cost function is mentioned in Example 4.7.1.) S.P.PB. 348