Exponential Functions with Percents

Which of the following could be represented by A=200(1.1)^t

• I started with $200 and lost 1% per week

• I started with $200 and lost 10% per week

• I started with $200 and gained 1% per week

• I started with $200 and gained 10% per week

Which represents "I started with $700 and increased it by 1% every year.

• y=700(1.1)^x

• y=700(1.01)^x

• y=700(0.99)^x

• y=700(0.9)^x

Which represents "I started with $700 and lost 1% every day"

• y=700(1.1)^x

• y=700(1.01)^x

• y=700(0.9)^x

• y=700(0.99)^x

Which one represents exponential growth?

• y=700(1.1)^x

• y=700(0.1)^x

• y=700(0.99)^x

• y=700(0.4)^x

The amount of ants in a colony, f, that is decaying can be modeled by                      f(x) = 800(.87)^x, where x is the number of days since the decay started. By what percentage is the colony decaying?

• 87%

• 13%

• 800%

• 8.7%

A student invests $500 for x years in a savings account that earns 4% interest per year. No further deposits or withdrawals are made during this time. Write an function f(x) to represent the amount of money earned after x years.

• f(x) = 500 (.60)^x

• f(x) = 500 (.96)^x

• f(x) = 500 (1.04)^x

• f(x) = 500 (1.4)^x

The population of deer on an island is given by P(x) = 100(0.85)^x, where x represents the number of years. Determine the percent of change the population of deer per year.

• 85% decrease

• 15% decrease

• 85% increase

• 15% increase

what is the percent increase/decrease of this exponential function?

y=47(1.09)^x

• A. 85% decrease

• B. 15% decrease

• C. 85% increase

• D. 15% increase

Which one represents exponential decay?

• A=200(1.1)^t

• A=200(0.1)^t

• A=200(99)^t

• A=200(9.9)^t