Exponential Functions Practice Test

Identify the function as exponential growth or decay, then find the rate as a percent.
y = a(0.89)^x

• Decay; 11%
• Decay; 89%
• Growth; 89%
• Growth; 11%

A population that initially has 10 birds approximately doubles every year.  Which graph represents this situation?

• A
• B
• C
• D

The exponential function modeled below represents the number of square kilometers of land occupied by cane toads x years after this animal was first introduced into Australia.  Based on the data, which measurement is closest to the number of square kilometers of land that will be occupied by cane toads 45 years after this animal was first introduced into Australia?

• 1,160,000
• 800,000
• 884,500
• No solution

What is the solution to the system of equations below?
-2x + 3y = 5
4x - 6y = 36

• No solution
• Infinite Solutions
• (2, -3)
• (5, 36)

The value in dollars, v9x), of a certain car after x years is represented by the equation v(x) = 32,000(0.72)^x .  To the nearest dollar, how much more is the car worth after 2 years than after 3 years?

• $4,645
• $16,589
• $11,944
• $32,000

A factory began producing new parts.  Data were collected on the number of defective parts per 10,000 parts produced.  The graph shown displays some of the data for the first 10 weeks of production.  Based on the graph, during which week were approximately 185 defective parts per 10,000 produced?

• Week 3
• Week 1
• Week 2
• Week 4

A population of 2000 deer decreases by 3.5% per year.  At the end of 10 years, there will be approximately 1,401 deer in the population.  Write a function that can be used to determine the number of deer, y, in this population at the end of t years?

• y = 2000(0.965)^t
• y = 2000(0.035)^t
• y = 2000(0.65)^t
• y = 2000(0.965)t

The table shows the population, p, of mice in a field at the end of m months.  Based on the data in the table, what will be the population of mice in the field at the end of 10 months?

• 6,144
• 66
• 12,288
• 3,072

A citywide youth tennis tournament has 64 players at the start. After each round, half the players are eliminated. The number of players remaining at the end of each round is given by the function  f(x) = 64(.5)^x  where x is the number of rounds played.  After how many rounds will there be only two players left?

• 5
• 4
• 3
• 6

The graph below shows the change in the value of a car over several years.  Based on the information in the graph, which of the following is a true statement about the graph?

• The value decreases about 24% each year.
• This is exponential growth.
• The value decreases 7,000 every 2 years.
• The value increases about 24% each year.