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

• The graph of this situation represents exponential decay.
• The range of this function is y > 0.
• There is a horizontal asymptote at y = 0 for this situation.
• The y-intercept is (0, 230).

Tags

CCSS.HSF-IF.C.7E

Daniel’s Print Shop purchased a new printer for $35,000. Each year it depreciates at a rate of 5%. How much will the printer be worth in 8 years?

• $23,219.72
• $136.72
• $51,710.94
• $16,710.94

Tags

CCSS.HSF.BF.A.2

Is this exponential growth or decay?

• Growth
• Decay

Tags

CCSS.HSF.LE.A.1

CCSS.HSF.LE.B.5

What type of function is y = 7(5/4)^x?

• Exponential Growth
• Exponential Decay
• Linear
• None of the above

Tags

CCSS.HSF-IF.C.8B

Suppose a culture of bacteria begins with 5000 cells and dies by 30% each year. Write an equation that represents this situation.

• y=5000(0.7)^x
• y=30(5000)^x
• y=5000(1.3)^x
• y=5000x^x

Tags

CCSS.HSF.LE.A.2

A 78 gram sample of Uranium loses half of its mass each year.  What is the exponential equation? 

• y=78(0.5)^x
• y=78(1.5)^x
• y=78(2)^x

Tags

CCSS.HSF.LE.A.2

What is the decay factor in the following model?
A=1200(.85)⁶

• 1200
• -.15
• .85
• A

Tags

CCSS.HSF-IF.C.8B

The half-life of Zn-71 is 2.4 minutes. If one had 100.0 g at the beginning, how many grams would be left after 7.2 minutes has elapsed?

• 100.0g
• 50.0g
• 12.5g
• 8.5g

Tags

CCSS.HSF.LE.A.4