Exponential Rates

In the function f(x)=142(1.005)^x , is this growth or decay and by how much?

• Growth by 5%

• Growth by 0.5%

• Decay by 5%

• Decay by 0.5%

In the function f(x)=1.25(0.65)^x , is this growth or decay and by how much?

• Growth by 25%

• Growth by 65%

• Decay by 25%

• Decay by 35%

In the function f(x)=200(1.7)^x , is this growth or decay and by how much?

• Growth by 70%

• Growth by 30%

• Decay by 30%

• Decay by 70%

Find the balance if a bank account starts with $100, has an annual rate of 4% and the money is left in the account for 12 years. Write answer as dollars and cents.

In 1985, there were 285 cell phone subscribers in a small town. That number increased by 75% per year after 1985. How many subscribers were there in 1994? (Round to nearest whole.)

Given that a particular bacteria doubles every hour, if we start with one bacteria, how many will there be at the end of one whole day?

The population of a certain town is modeled by f(x)=6191(1.04)^x . By what percent did the population increase by each year?

You inherited land purchased for $30,000 in 1970. The value of the land increased by 5% each year. What would the value of the land be in 2021? (Write in terms of dollars and cents.)

You buy a new computer for $2,100. The computer decreases by 50% annually. When will the computer have a value of less than $500?

• Between year 1 and 2.

• Between year 2 and 3.

• Between year 3 and 4.

You drink a beverage with 120 mg of caffeine. Each hour, the caffeine in your system decreases by about 12%. How long until you have 10 mg of caffeine?

• Between 13 and 14 hours.

• Between 19 and 20 hours.

• Between 23 and 24 hours.

• Between 10 and 11 hours.