Resources

Resources

Exponential growth and decay: word problems

A new car is purchased for

23400

dollars. The value of the car depreciates at

5.75 \%

per year. What will the value of the car be, to the nearest cent, after

9

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A town has a population of

17000

2 \%

every year. What will be the population after

12

years, to the nearest whole number?

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4800

dollars is placed in an account with an annual interest rate of

6.5 \%

. How much will be in the account after

14

years, to the nearest cent?

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7400

dollars is placed in an account with an annual interest rate of

8 \%

. How much will be in the account after

19

years, to the nearest cent?

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A new car is purchased for

18400

dollars. The value of the car depreciates at

10.75 \%

per year. What will the value of the car be, to the nearest cent, after

9

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5000

dollars is placed in an account with an annual interest rate of

8.75 \%

. How much will be in the account after

18

years, to the nearest cent?

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A new car is purchased for

16900

dollars. The value of the car depreciates at

15 \%

per year. What will the value of the car be, to the nearest cent, after

15

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A town has a population of

19000

4.5 \%

every year. What will be the population after

9

years, to the nearest whole number?

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A town has a population of

13000

2 \%

every year. What will be the population after

12

years, to the nearest whole number?

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7700

dollars is placed in an account with an annual interest rate of

8 \%

. How much will be in the account after

22

years, to the nearest cent?

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A town has a population of

17000

3.5 \%

every year. What will be the population after

9

years, to the nearest whole number?

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A new car is purchased for

15600

dollars. The value of the car depreciates at

14.5 \%

per year. What will the value of the car be, to the nearest cent, after

10

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The population of a town is

500,000

. If the population growth rate is

6\%

yearly, when will the population exceed

600,000

? (Express the answer correct to the nearest integer.)

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2

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3

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4

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5

A company has the goal of doubling their revenue from

x

million dollars to

2x

million dollars over the next

n

years. If the company increases its revenue by

y\%

in the first year, by approximately what percentage must the company increase their revenue in the second year in order to reach their goal?

A company has the goal of doubling their revenue from

\$

32

\$

64

million over the next

2

years. If the company increases its revenue by

50

`%` in the first year, by approximately what percentage must the company increase their revenue in the second year in order to reach their goal?

An executive in an engineering firm earns a monthly salary plus a Christmas bonus of

\$6900

and earns a total of

\$99100

per year, what is her monthly salary in dollars?

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Your answer is :

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\$

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Give your answer to the nearest cent.

Bacteria in a culture increase at a rate that is proportional at any time to the number of bacteria at that time.

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800

bacteria initially, and they triple every

10

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What is the number of bacteria after

4

hours? Round to the nearest integer.

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\square

The number of barrels of oil a certain company exports annually increases at a rate that is proportional at any time to the number of barrels they export at that time.

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The company exported

5

4

million barrels annually initially, and it exported

10

8

million barrels annually after

6

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How many million barrels of oil did the company export annually after

10

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Round to the nearest integer.

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\square

million barrels

1.5 t+20

predicts the height in centimeters of a plant

t

days from today.

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What is the predicted height of the plant

5

days from today?

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\mathrm{cm}

A software distributor charges

\$ 41

per license of a particular utility. The distributor offers a

10 \%

discount on each license after the first

20

. How much would a business pay to buy

40

licenses of the utility, in dollars?

Each year, Francesca earns a salary that is

2 \%

higher than her previous year's salary. In her first

5

years at this job, she earned a total of

\$ 187,345

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What was Francesca's salary in her

1^{\text {st }}

year at this job?

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Round your final answer to the nearest thousand.

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A new shopping mall is gaining in popularity. Every day since it opened, the number of shoppers is

20 \%

more than the number of shoppers the day before. The total number of shoppers over the first

4

671

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How many shoppers were at the mall on the first day?

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Round your final answer to the nearest integer.

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A new shopping mall is gaining in popularity. Every day since it opened, the number of shoppers is

5 \%

more than the number of shoppers the day before. The total number of shoppers over the first

10

1258

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How many shoppers were at the mall on the first day?

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Round your final answer to the nearest integer.

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\$ 39,000

salary in the first year of her career. Each year, she gets a

5 \%

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How much does Emma earn in total in the first

11

years of her career? Round your final answer to the nearest thousand.

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One marketing professional recommends that businesses budget between

12 \%

16 \%

of their monthly gross sales for rent. If a business earns

\$ 540,000

in gross sales per year, how many dollars would the adviser recommend as the maximum budget for rent each month?

4 \%

commission for the first

\$ 30,000

of sales he makes per month. He earns a

5 \%

commission for the portion of his sales over

\$ 30,000

. If Dyami sells

\$ 38,000

worth of merchandise in a month, how much will he earn in commissions, in dollars?

12,000

\mathrm{BTU}

air conditioner running six hours each day will consume

270

(\mathrm{kWh})

in a month. If the monthly cost of electricity for the air conditioner is

\$ 32.40

, what is the cost of electricity in cents per kilowatt-hour?

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(Round the answer to the nearest integer.)

In a particular research database, the number of indexed genetics articles had increased by an average of

307

articles per year for several years. At the end of that time period, there were

6000

genetics articles indexed. Since then, the number of articles has increased by

8 \%

annually. To the nearest whole number, how many more genetics articles are there after

2

years of this increase than if the growth rate had not changed?

1.5 t+20

predicts the height, in centimeters, of a plant

t

days from today. What is the predicted height, in centimeters, of the plant

5

days from today?

100

bacteria doubles in size every

60

hours. What will the population be

180

?

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