Section: 1.3 / Models and Applications / Day 1 of 1
Problem Solving with Linear Equations
Celebrity Earnings
Forbes magazine published a list of the highest paid TV celebrities between June 2006 and
2007. The results are shown in the figure below.
The bar heights indicate that nobody came close to Oprah, who earned over four times more than any other TV stars. Although Seinfeld earned $15 million more than Cowell, Oprah’s earnings exceeded Cowell’s by $215 million. Combined, these three celebrities earned $365 million. How much did each celebrity earn?
Modeling Attitudes of College Freshmen
Researchers have surveyed college freshmen every year since 1969. The figure to the right shows attitudes about some life goals havechanged dramatically. The figure also shows that the freshmen class of 2006 was more interested in making money than the freshman of1969 had been. In 1969, 52% of first-year college men considered “being very well off financially” essential or very important. For the
period from 1969 through 2006, this percentage increased by approximately 0.6 each year. If this trend continues, by which yearwill all male freshmen consider “being very well off financially” essential or very important?
Selecting a Long-Distance Carrier
You are choosing between two long-distance telephone plans. Plan A has a monthly fee of $20 with a charge of $0.05 per minute for all long-distance calls. Plan B has a monthly fee of $5 with a charge of $0.10 per minute for all long-distance calls. For how many minutes of long-distance calls will the costs for the two plans be the same?
Solving a Dual Investment Problem
Your grandmother needs your help. She has $50,000 to invest. Part of this money is to be invested in noninsured bonds paying 15% annual interest. The rest of the money is to be invested in a government-insured certificate of deposit paying 7% annual interest. She told you she requires $6000 per year in extra income from the combination of those investments. How much money should be placed in each investment?
Finding the Dimensions of a Football Field
The length of an American football field is 200 feet more than the width. If the perimeter of the field is 1040
feet, what are its dimensions?
Solving a Formula for One of its Variables
Solving a Formula for a Variable
- The formula A = P + Prt describes the amount A, that a principal of P dollars is worth after t years when invested at a simple annual interest rate, r. Solve this formula for P.
- Solve for C: