Free Printable Growth and Decay

Worksheets

Growth and Decay

Total questions: 28

Worksheet time: 2hrs 33mins

Name

Class

Date

Is this exponential growth or decay?

Growth, because of 7

Decay, because of 1.2

Growth because of 1.2

Decay because of 7

P = 8(1.23)^t

What is the growth rate?

Write as a percent!

(a)

P = 8(1.23)^t

What is the initial quantity?

(a)

P = 8(1.23)^t

Is the function growth or decay?

Check the box:

Growth

Decay

Q = 3.1(0.78)^t

What is the DECAY rate?

Write as a percent!

CAREFUL!!!

(a)

The value of a car is $15,000 and depreciates at a rate of 8% per year. What is the exponential equation?

y=8(15,000)^x

y=15,000(1.08)^x

y=15,000(0.92)^x

y=15,000(0.08)^x

An air freshener starts with 30 grams of fluid, and the amount of fluid decreases by 12% per day. Express the amount of grams of freshener, Q, that remains, t, days after it has begun being used.

Check the BEST answer: (HINT: that means simplify what is in the parenthesis)

Q=30(1+0.12)^t

Q=30(1-0.12)^t

Q=30(0.88)^t

Q=12(1.30)^t

Pick the equation that is exponential decay

y=2000(0.88)

y=0.5(1.88)

y=-4x

y= -7+10x

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?

It doesn't say

I don't know

400%

10.

A 78 gram sample of Uranium loses half of its mass each year. What is the exponential equation?

y=78(0.5)^x

y=78(1.5)^x

y=78(2)^x

11.

Pick the equation that is exponential growth

y=2(0.5)^x

y = 0.5(2)^x

y = .5x - 2

y = 2x + .5

12.

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

13.

The population of Winnemucca, Nevada, can be modeled by P=6191(1.04)^twhere 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

14.

You start an account with $500 and an interest rate of 6% compounded yearly. How much is in the account after 3 years?

Round to the nearest cent. (two decimal places)

(a)

15.

More and more people are purchasing food from farmers' markets. As a consequence, a market researcher predicts that the number of farmers' markets will increase by 15% each year. If there are 6,200 farmers' markets this year, how many will there be in 10 years? (Round to the nearest whole number if necessary).

25,082

12,937

62,000

43,511

16.

A publishing industry report predicts that magazine subscriptions will drop by 10% each year. If this prediction is correct, then how many subscribers will a magazine with 98,000 subscribers have in 10 years? (Round to the nearest whole number if necessary).

34,170

16,348

7690

76,023

17.

Jenny has $20 in a savings account. The interest rate is 5%, compounded annually. To the nearest cent, how much interest will she earn in 2 years?

$2.05

$45.79

$1.99

$7.51

18.

Thanks to its environmental initiatives, Silvergrove has cut its annual CO2 emissions by 5%. This year, the town produced 290,000 metric tons of emissions. If the downward trend continues, how much CO2 will be produced 7 years from now? (Round to the nearest whole number if necessary).

202,518

135,792

78,376

20,658

19.

The mice population is 25,000 and is decreasing by 20% each year. What will be the mice population after 3 years?

12,800

15,777

102, 475

2,500

20.

Your new computer cost $1500 but it depreciates in value by about 18% each year. How much will your computer be worth in 6 years? (Round to the nearest cent.)

$456.01

$556.98

$778.22

$332.63

21.

You have inherited land that was purchased for $30,000 in 1960. The value of the land increased by approximately 5% per year. What is the approximate value of the land in the year 2011?

$344,022

$31,500

$15,000

$28,500

22.

During normal breathing, about 12% of the air in the lungs is replaced after one breath. Write an exponential decay model for the amount of the original air left in the lungs if the initial amount of air in the lungs is 500 mL. How much of the original air is present after 240 breaths?

Just about zero mL

60 mL

440 mL

0 mL

23.

You bought a Boston Whaler in 2004 for $12,500. The boat's value depreciates by 7% a year. How much is the boat worth in 2012?

$11625

$6994.77

$21,477

$875

24.

Suppose you deposit $3000 in a savings account that pays interest at an annual rate of 4%. If no other money is added or withdrawn from the account, how much will be in the account after 10 years?

$3122.18

$4994.50

$4440.73

$86,776.40

25.

The attendance at the art museum at the New Year’s opening was 250 people. The attendance has been increasing at a rate of 3% each month. How many people will attend by the end of a year?

356

265

5825

1329

26.

The population of turtles is doubling every 3 months. If there are 400 turtles now, how many will there be in 2 years? (Choose equation)

y = 400(2)²

y = 400(2)⁶

y = 400(2)⁸

y = 400 + 2(8)

27.

Anakin invested $300 in an account with interest compounded continuously. No other money was deposited or withdrawn. In 12 years the amount in the account was $500. What was the annual interest rate?

4.25%

3.15%

5.0%

2.8%

28.

If a savings fund pays interest at a rate of 6% per year compounded semiannually, how much money invested now will amount to $4000 after 4 years?

3020

5100

3160

1008

100 %

Growth and Decay

Total questions: 28

Worksheet time: 2hrs 33mins

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