Word problem help: how many of each coffee should he buy?

[Guest]

I have never been someone who has luck with word problems and would LOVE some help with this.

Phil is making a Starbuck’s ® run for his exhausted Math 105 classes. He is going to buy a combination of Lattes and Cappuccinos. The Lattes cost $4 each and the Cappuccinos cost $3 each. If he needs 30 drinks total and has $100 to spend, how many of each should he buy?

Thank you to whoever
Andrea

 

[stapel]

A good way to start would be to figure out what you have and what you need.

Pick variables to stand for the numbers of each type of drink. What then is their sum? This is your first equation.

How much is one latte? How much for two? Three? How much for (variable name) lattes?

How much is one cappuccino? How much for two? Three? How much for (variable name) cappuccinos?

Then what is the cost for the total order? This is your second equation.

If you know how to solve systems of equations, use that method. If not, then solve the first equation for one of the variables (something like "y = 30 - x"), and plug that in for that variable in the second equation. Solve.

If you get stuck, please reply showing how far you have gotten in following the instructions. Thank you.

Eliz.