Jenna's doctor tells her that she should tan no more than 200 minutes a month. If she tans 30 minutes a day, two days a week for the first two weeks of the month, how many minutes can she tan in the last two weeks of the month?
Thoughts? Step-by-step reasoning:
First find how many minutes Jenna tans each of the first two weeks: 30 minutes / day * 2 days / week = 60 minutes / week. Then multiply that number by the number of weeks to find how many minutes Jenna tans in the first half of the month: 60 minutes / week * 2 weeks = 120 minutes. Then subtract that time from the total time Jenna can spend tanning to find how many more minutes she can tan: 200 minutes - 120 minutes = 80 minutes.
Thus, the answer is 80.