The quantity produced by a firm is given by the production functionQ(K,L) = 30K1/5L1/4

whereKis the amount of capital andLis the amount of labour used in the production process.

Each unit of capital costswK = 3 and each unit of labour costswL = 4, and the firm sells its

product at fixed pricep= 5.

(i) Write down the firm's profit as a function ofKandL.