Suppose that a radio production function of broadcasting per day (M) is M=S * N, where S is the number of songs and N represents news (measured in hours). The copyright fee (price) of a song is Ps and the cost of one hour of news broadcasting is Pn.

Currently, radio have 4 hours of daily news. Write down the short-run variable cost and marginal cost function of Radio.

Can you calculate short-run variable cost and marginal cost function for this problem?