5-14 A2 Chapter 6 Word Problems

A population of 1500 deer decreases by 1.5% per year. At the end of 10 years, there will be approximately 1290 deer in the population. Which function can be used to determine the number of deer, y, in this population at the end of t years?

• y = 1500(1 - 0.015)^t

• y = 1500(0.015)^t

• y = 1500(1 + 0.015)^t

• y = 1500(1.5)^t

There were 417 cell phones sold at an electronics store in January. Since then, cell phone sales at this store have increased at a rate of 3.75% per month. At this rate of growth, which function can be used to determine the monthly cell phone sales x months after January?

• f(x) = 417(3.75)^x

• f(x) = 417(0.0375)^x

• f(x) = 417(1.0375)^x

• f(x) = 417(1.375)^x

• x > 0

• y > 0

• -∞ < x < ∞

• -∞ < y < ∞

Some banks charge a fee for a savings account that is left inactive for an extended period of time. The equation y = 5000(0.98)^x represents the amount remaining, y, of one account that was left inactive for a period of x years. What does the number 5000 represent in this situation?

• A fee charged for an inactive account

• The percent of money in the account after x years

• The amount of money in the account initially

• The amount of money in the account after x years

A child asks her dad for an allowance that starts with a penny and then doubles every day for a month. Which function can be used to model the amount of money, A, the child will receive each day, x?

• A(x) = 2(0.01)^x

• A(x) = 0.01(2)^x

• A(x) = 0.01(1 - 2)^x

• A(x) = 2(1.01)^x

• F

• G

• H

• J

Middletown High School has student elections every year. Lately, the school has seen a 5% decrease in voting from election to election. If 910 students voted this year, how many will be expected to vote 8 years from now? (Round to the nearest whole number if necessary).

• 604

• 777

• 29

• 198

You drink a beverage with 120 mg of caffeine. Each hour, the caffeine in your system decreases by about 12%. How long until you have 10mg of caffeine? 

• 19 to 20 hours

• 10 to 20 hours

• 15 to 16 hours

• 5 to 6 hours

The foundation of your house has about 1,200 termites. The termites grow at a rate of about 2.4% per day. How long until the number of termites doubles?

• 29 to 30 years

• 23 to 24years

• 15 to 16 years

• 19 to 20 years

Karla invested $1,000 in savings bonds. If the bonds earn 6.75% interest compounded semi-annually, how much total will Karla earn in 15 years?

• $1,584.62

• $2,651.39

• $2,706.86

• $1,825.10