Maddie wants to see how much her mom spends on coffee each week. She makes herself 2 cups of coffee per day. Each cup has 1.5 ounces of coffee beans. A bag of coffee costs $8 and contains 10.5 ounces of beans. She uses 1/2 a gallon of milk per week. A gallon of milk costs $4. She doesn't add any sugar to the coffee. How much does she spend on her coffee per week?
Thoughts? Step-by-step reasoning:
She uses 3 ounces of beans per day because 2 x 1.5 = 3. She uses 21 ounces of beans per week because 7 x 3 = 21. She buys 2 bags of beans per week because 21 / 10.5 = 2. She spends $16 on the beans per week because 2 x 8 = 16. She spends $2 on the milk per week because 4 x (1 / 2) = 2. She spends $18 per week on her coffee because 16 + 2 = 18.
Thus, the answer is 18.