9. Mark drinks one cup of coffee everyday. He orders a coffee from Dunkin Donuts and it costs him $3.50 everyday. He is starting to think that he might buy a Keurig and k-cups instead. The Keurig is $150 and each k-cup costs $0.50. How many cups of coffee will it take for the cost at Dunkin Donuts to be the same as having a Keurig and k-cups?

Respuesta :

Answer: 50 cups of coffee

Step-by-step explanation:

Let x represent the number of cups of coffee that it will take for the cost at Dunkin Donuts to be the same as having a Keurig and k-cups.

He orders a coffee from Dunkin Donuts and it costs him $3.50 everyday. It means that the cost of ordering x cups would be 3.5x.

The Keurig is $150 and each k-cup costs $0.50. It means that the cost of ordering x cups would be 150 + 0.5x.

For the ordering cost to be the same, it means that

3.5x = 150 + 0.5x

3.5x - 0.5x = 150

3x = 150

x = 150/3

x = 50