The monthly cost to produce x tyres is given by C(x) = 100x − 0.03x^2 + 0.000004x^3 for 0 ≤ x ≤10000 with a fixed cost of 75,000 and the demand function for the tyres is given by,p(x) = 200 − 0.005x for 0 ≤ x ≤ 10000 Determine the marginal cost, marginal revenue and when 2500 tyres are sold and when 7500 tyres are sold. Assume that the company sells exactly what they produce.