Real World Exponential Equations

Ms. Colunga bought a new car, which cost him $30,000. Which equation represents how long it will take for the value of the car to be $15,000, if the car depreciates at a rate of 18% per year?

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

• 0 people

• It doesn't say

• I don't know

• 6191

The population of Winnemucca, Nevada, can be modeled by P=6191(1.04)^t where t is the number of years since 1990. What percent did the population increase each year?

• 4%

• It doesn't say

• I don't know

• 400%

You buy a new computer for $2100. The computer decreases by 50% annually. When will the computer have a value of $600?

• between 1 and two years

• more than 5 years

• less than a year

• between 3 and 4 years

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 10mg of caffeine?

• 19 to 20 hours

• 10 to 20 hours

• 15 to 16 hours

• 5 to 6 hours

Jane has a hard time waking up before she drinks a tall latte with 140 mg of caffeine. Each hour, the amount of caffeine in her system decreases by 13%. How long until she only has 26 mg of caffeine?

• t=17.066

• t=13.895

• t=12.089

• t=26.891

What does the graph represent?

• Exponential Growth

• Exponential Decay

A car bought for $13,000 depreciates at 15% per year. Use and exponential function to find the value of the car after 5 years.

• $3698.00

• $26,000

• $4020.00

• $5768.17

What does this graph represent?

• Exponential Growth

• Exponential Decay

The original value of a painting is $1400, and the value increases by 9% each year. Write an exponential growth function to model this situation.

• y=1400(1.09)^x

• y=1.09(1400)^x

• y=1400(.91)^x

• y=1.09^x