Final answer:
The combination that minimizes Joe's weekly cost is 6 healthy meals and 15 fast food meals. By choosing this combination, Joe can get the nutrients he needs and save money. However, relying heavily on fast food may lead to health problems in the long run.
Step-by-step explanation:
The combination of fast food meals and healthy meals that minimizes Joe's weekly cost is option c: 6 healthy meals and 15 fast food meals.
By choosing 6 healthy meals, Joe can ensure he is getting the nutrients he needs and reduce the risk of health issues caused by consuming too much unhealthy food. Additionally, by opting for more fast food meals, Joe can save money on his weekly cost.
However, it's important to note that relying heavily on fast food may still lead to health problems in the long run, such as obesity, heart disease, and high blood pressure. So it's always beneficial to incorporate as many healthy choices as possible.