Exponential Growth and Decay Word Problems and Tables

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

The population of Bloom Falls, Mass. (population 937) is slowly moving to a bigger city.
Every year the population drops by 4.5%. What is the population after 3 years?

• 1,069 people

• 894 people

• 816 people

• 854 people

In 1985, there were 285 cell phone subscribers in the small town of Centerville. The number of subscribers increased by 75% per year after 1985. How many cell phone subscribers were in Centerville in 1994?

• 305

• 1994

• 1000

• 43872

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(1+14)^x

• y=6(1.14)^x

• y=6(0.86)^x

Suppose a culture of bacteria begins with 5000 cells and dies by 30% each year. Write an equation that represents this situation.

• y=5000(0.7)^x

• y=30(5000)^x

• y=5000(1.3)^x

• y=5000x^x

If you have $10, and your money doubles every year, how much money will you have in 10 years?

• $50

• $100

• $5120

• $10240

Classify the model as Exponential GROWTH or DECAY.
A=1200(.85)⁶

• Growth

• Decay

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

The value of a car is $15,000 and depreciates at a rate of 8% per year. What is the decay factor? Hint: decay factor is (1-r) where r is the rate as a decimal

• ^.08

• ^1.08

• .92

• 8

If the decay rate is 20%, which of the following represent the decay factor?

• 0.2

• 0.8

• 1.2

• 1.8