Exponential Word Problems Find the Decay or Growth

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

Annual sales for a fast food restaurant are $650,000 and are increasing at a rate of 4% per year. Use an exponential function to find the annual sales after 7 years.

Round to two decimal places (like dollars and cents).

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).

Using the exponential function equation f(x)=ab^x, where a is the starting value and b is the growth or decay, and x is the time, find the value of a house after 15 years if it initially worth $250,000 and increases by 5% each year.

• $405,518.75

• $500,000

• $425,000

• $375,000

Using the exponential function equation f(x)=ab^x, where a is the starting value and b is the growth or decay, and x is the time, find the population of bacteria after 5 hours if it doubles every hour and initially has 100 bacteria.

• 500

• 3200

• 2000

• 1000

The value of a car purchased for $20,000 decreases at a rate of 12% per year. What will be the value of the car after 3 years?

• $12,800.00

• $13,629.44

• $17,600.00

• $28,098.56

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 days

• 23 to 24 days

• 15 to 16 days

• 19 to 20 days

The population of Winnemucca, Nevada, can be modeled by P=6191(1.04)^t where t is the number of years since 1990. What is the population of the town 21 years later?

• 6191

• 9912

• 72519

• 14108

Using the exponential function equation f(x)=ab^x, where a is the starting value and b is the growth or decay, and x is the time, find the population of fish after 8 weeks if the population doubles every week and initially there are 1000 fish.

• 128000

• 512000

• 64000

• 256000