Exponential Growth and Decay

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

Tags

CCSS.HSF.LE.A.2

An antibiotic is introduced into a colony of 12,000 bacteria during a laboratory experiment. The colony is decreasing by 14.9% per minute. Which function can be used to model the number of bacteria in the colony after x minutes?

• f(x) = 12000(1 + 14.9)^x
• f(x) = 12000(1 - 14.9)^x
• f(x) = 12000(1 + 0.149)^x
• f(x) = 12000(1 - 0.149)^x

Tags

CCSS.HSF.LE.A.2

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

Tags

CCSS.HSF.LE.B.5

A population of fish starts at 8,000 and decreases by 6% per year. What is the population of fish after 10 years?

• 14327
• 4309
• 839
• 7680

Tags

CCSS.7.RP.A.3

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

• 16

• 5433

Tags

CCSS.HSF.BF.A.2

Classify the model as Exponential GROWTH or DECAY.
A=10(1.01)³

• Growth
• Decay

Tags

CCSS.HSF-IF.C.8B

You have inherited land that was purchased for $30,000 in 1970. The value of the land increased by 5% per year. What is the approximate value of the land in the year 2021?

• $361,000

• $31,500

• $106,500

• $222,000

An adult takes 800 mg of ibuprofen. Each hour, the amount of ibuprofen in the person’s system decreases by about 29%. How much ibuprofen, rounded to the nearest whole mg, is left after 6 hours?

• 101

• 102

• 103

• 104

Identify each function as representing exponential growth or decay.
f(x) = 4(0.89)^x

• growth
• decay

Tags

CCSS.HSF-IF.C.8B

Olivia would like to buy some new furniture for her home. She decides to buy the furniture on credit with 9.5% interest compounded quarterly. If she spent $7,400, how much total will she have paid after 8 years.

• $15,415.94
• $15,683.28
• $15,927.56
• $16,109.05

Tags

CCSS.HSF.LE.A.2

CCSS.HSA.CED.A.1

CCSS.HSA.SSE.A.1

CCSS.HSA.SSE.B.4

CCSS.HSF.BF.A.1

CCSS.HSF.LE.A.1