
Yefim S. answered 05/04/22
Math Tutor with Experience
Revenue R(x) = xp = x(120 - 0.05x) = 120x - 0.05x2;
Profit P(x) = R(x) - C(x) = 115x - 500 - 0.05x2;
P'(x) = 115 - 0.1x = 0; x = 1150
P''(x) = - 0.1 < 0. So, at x = 1150 we have maximum profit and price is p = 120 - 1150·0.05 = 62.50