A political candidate wants to use a combination of radio and TV advertisements in her campaign. Research has shown that each 1-minute spot on TV reaches 0.9 million people and that each 1-minute spot...

A political candidate wants to use a combination of radio and TV advertisements in her campaign. Research has shown that each 1-minute spot on TV reaches 0.9 million people and that each 1-minute spot on radio reaches 0.8 million. The candidate believes she must reach 72 million people, and she must buy at least 65 minutes of advertisements. How many minutes of each medium should be used if TV costs $800 per minute, radio costs $200 per minute, and the candidate wishes to minimize costs?