$3$ A politician is budgeting for her media campaign. She will distribute her funds between TV ads and radio ads. She has been given the following advice by her campaign advisors: Question $2$ She should run at least $120$ TV ads and at least $30$ radio ads. The number of TV ads she runs should be at least twice the number of radio ads she runs but not more than four times the number radio ads she runs. $-$ The cost of a TV ad is $$5,000$ and the cost of a radio ad is $$2,500.$ Which combination of TV and radio ads should she choose to minimize the cost of her media campaign? Write down your answer$($s the text box below. In addition, you should show the followings on your scratch papers for full credit. W A$.$ Define the unknowns. B$.$ Construct the linear programming problem and solve it using the geometric method.