Finding Values of Exponential Functions Word Problems

A newly launched clothing line is rapidly increasing in popularity. Every month, 20% more items of clothing are sold. If 89,090 items were sold this month, how many will be sold in 9 months from now? If necessary, round your answer to nearest whole number.

• 74,278 items.

• 11,957 items.

• 319,226 items.

• 459,685 items.

Katy deposited $90 in a savings account earning 5% interest, compounded quarterly. Which of the following equations could represent the amount of money in her account yearly?

• 
• 
• 
• 

Derrick has $1,000 in a savings account that ears 15% interest, compounded monthly. To the nearest cent, how much will he have in 2 years?

• $5,350.25

• $1,322.50

• $1,025.16

• $1,347.35

A city doubles its size every 64 years. If the population is currently 225,000, what will the population be in 128 years?

• The population will be 225,000.

• The population will be 450,000.

• The population will be 900,000.

• The population will be 1,800,000.

You have 30,016 grams of radioactive kind of rubidium. How much will be left after 54 minutes if its half-life is 18 minutes?

• 15,008 grams.

• 7,504 grams

• 3,752 grams.

• 1,876 grams.

Find the balance in an account that has $300 invested at 6.5% for 4 years compounded semi-annually.

• $387.47

• $496.50

• $7,800.00

• $385.94

A particular type of cell triples in number every hour. Which function can be used to find the number of cells present at the end of h hours if there are initially 6 of these cells?

• f(h) = 3(6)^h

• f(h) = 6x^h

• f(h) = 6(3)^h

• f(h) = 3(6h)

The amount of cola in a soda machine decreases by a rate of 5% each hour. The amount of cola in the machine was originally 75 gallons. Which function models the amount of cola in gallons after h hours?

• f(h) = 75(-5)^h

• f(h) = -5(75)^h

• f(h) = .95(75)^h

• f(h) = 75(.95)^h

Write an exponential function to model the situation. Then solve. The cost of tuition at a college is $12,000 and is increasing at a rate of 6% per year. Which equations represents this situation?

• C(t) = 1.06(12000)^t

• C(t) = 12000(.06)^t

• C(t) = 12000(.06)^t

• C(t) = 12000(1.06)^t

Write an exponential function to model the situation. You invest $1500. Your investment increases at a rate of 3.5%.

• B(t) = 1500(0.965)^t

• B(t) = 1500(1.035)^t

• B(t) = 1500(.035)^t

• B(t) = 1500(1.965)^t