Exponential Decay Problems

The population of a town is 2500 and is decreasing at a rate of 3.5% per year. Use an exponential function to find the population of the town after 5 years.

Round to the nearest whole number (you can't have a fraction of a person).

Kathy plans to purchase a car that depreciates at a rate of 12% per year. The initial value of the car is $21,000. Use an exponential function to find the value of the car after 3 years.

Round your answer to 2 decimal places.

A population of fish starts at 8,000 and decreases by 6% per year. Use an exponential function to find the population of fish in 10 years.

Round to the nearest whole number.

• Initial amount

• Rate of growth or decay

• Time

• End amount

Which represents exponential decay?

• A

• B

• C

• D

The population of Townville is decreasing at a rate of 6% each year. If the starting population was 7,000 what equation represents the current population after x number of years?

At a certain point in time, a fossil has 3 picograms of carbon-14. Complete the table with the missing mass of carbon-14 and years

a

b

c

1.5

11,460

2.38

Choose the correct graph for the situation on problem #5

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Graph the exponential function that has a starting value of 8 and decreases by 12.5%.

Set the dotted line to y = 0.

Which of the following best represents the graph?

• y=2^x

• x=2^y

• y=x²

• y=2^-x