Exponential Functions

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(114)^x

• y=6(1.14)^x

• y=6(0.86)^x

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

A collectible car has been going up in price by 10% each year. If the car is already worth $29,000, how much will the car be worth in 5 years?

• $0.29

• $2,900,000

• $46,704.79

• $145,000

The population of wolves in a certain place was 5,450 in 2013. Each year the population has decreased by 5%. What equation models the population of wolves since 2013?

• p(x) = 5450(95)^x

• p(x) = 5450(0.05)^x

• p(x) = 5450(0.95)^x

• p(x) = 5450 (1.05)^x

The population of a bacterial culture grows at a rate of 4.5% every hour. If there were 200 bacteria at the start, how many bacteria are present after 10 hours?

• 250

• 300

• 310

• 370

A new savings account is opened with $400 and gains 3% every year. What is the exponential function?

• f(x)=400(103)^x

• f(x)=400(0.97)^x

• f(x)=400(1.03)^x

• f(x)=400(0.03)^x

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

The attendance at the art museum at the New Year’s opening was 250 people. The attendance has been increasing at a rate of 3% each month. How many people will attend by the end of a year?

• 356
• 265
• 5825
• 1329

You buy a new computer for $2100. The computer decreases by 50% annually. How much is it worth after 2 years.

• 225
• 325
• 425
• 525