Exponential Growth Story Problems

The number of mosquitoes at the beginning of the summer was 4,000. The population of mosquitoes is expected to grow at a rate of 25% a month. How many mosquitoes will there be after 4 months?

• 9766

• 9006

• 9765

• 5433

If you have $10, and your money doubles every year, how much money will you have in 10 years?

• $50

• $100

• $5120

• $10240

Which of the following functions shows an initial amount of $15 and an increase of 35% each year?

• y = 15(35)^x

• y = 15(1.35)^x

• y = 15(0.35)^x

• y = 35(1.15)^x

Write an equation that models the following situation: Samantha's hair was known to grow very rapidly. It began at a length of 6 in and grew at a rate of 14% a week.

• y=6(0.14)^x

• y=6(1+14)^x

• y=6(1+ 0.14)^x

• y=6(1 - 0.14)^x

Hint: use a graph and/or table of values to determine the answer

• approximately 16 years

• approximately 6 years

• approximately 10 years

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.

Bruno was given $2000 when he turned 3 years old. His parents invested it at a 2% interest rate compounded annually. No deposits or withdrawals were made. Which expression can be used to determine how much money Bruno had in the account when he turned 16?

• 2000(1+0.02)¹³

• 2000(1-0.02)¹³

• 2000(1+0.02)¹⁶

• 2000(1-0.02)¹⁶

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

You have inherited land that was purchased for $30,000 in 1960. The value of the land increased by approximately 5% per year. What is the approximate value of the land in the year 2019?

• $533,691

• $31,500

• $15,000

• $28,500

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