1.3 Problem-Solving Procedures 23 The following examples show how to apply the guidelines for problem solving. Example 2 Ride-Share Service Latricia uses a ride-share service to travel to her local airport. Ride-share services use an app available on smartphones. Ride-share services have increasingly taken business away from traditional taxi services. The total fare that Latricia is charged includes a base fee plus a mileage fee plus a time fee. The base fee is $5.00, the mileage fee is calculated at $1.10 permile, and the time fee is calculated at $0.21perminute. The distance Latricia will travel to the airport is 17 miles, and it will take 25 minutes to get there. Use this information to determine Latricia’s total fare for using the ride-share service to travel to the airport. Solution We need to determine the total fare that Latricia is charged to travel to the airport. We will make a list of the information given and mark with an asterisk (*) the information that is pertinent to solving the problem. Ride-share services use an app available on smartphones. Ride-share services have increasingly taken business away from traditional taxi services. * Latricia is charged a base fee plus a mileage fee plus a time fee. * The base fee is $5.00. * The mileage fee is calculated at $1.10 permile. * The time fee is calculated at $0.21 perminute. * Latricia will travel 17 miles to the airport. * It will take 25 minutes to get to the airport. The first two items listed are not needed to solve the problem. To determine the total fare, we first must calculate the mileage fee and the time fee. Mileage fee $1.10 per mile 17 miles $18.70 Time fee $0.21 per minute 25 minutes $5.25 = × = = × = The total fare is the sum of the base fee, the mileage fee, and the time fee. = + + = + + = Total fare Base fee Mileage fee Time fee $5.00 $18.70 $5.25 $28.95 Thus, Latricia is charged $28.95 for using the ride-share service to travel to the airport. 7 Now try Exercise 23 In our next example, we will continue to use the guidelines for problem solving. Example 3 Retirement It is never too early to start planning for retirement. U.S. Census Bureau data indicate that about 33% of the average person’s retirement income will come from Social Security. When discussing retirement planning, many investment firms and financial planners use the graph in Fig. 1.1, which shows how long a typical retiree’s assets will last based on the percentage of the assets withdrawn each year. a) If a typical retiree has retirement assets of $500,000, how much can be withdrawn annually if the assets are to last 21 years? b) If the retiree wishes to withdraw $25,000 annually and if the assets are to last 18 years, how much should the retiree have in assets? Bhpix/Shutterstock
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