You buy a cell phone plan that gives you up to 1000 minutes of calling for $20 per month. During a particular month, you use only 100 minutes. What is your per-minute cost for that month?

Hello Cassidy,
To solve this problem, you could use a proportion to solve for your question. I have attached the work as well. On the top of your fractions, can be the money. On the bottom is the minutes. Note: these can be interchangeable, as long as all your numeric values (numbers) and variables are in the right place. Then cross-multiply. Solve the equation for your answer (money for minutes). I used the variable m, as I find it helps if it relates to your problem. M is for money. Hope this helps!