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