Worksheets4.2 Exponential Decay
Total questions: 10
Worksheet time: 50mins
Name
Class
Date
1.
Suppose a culture of bacteria begins with 5000 cells and dies by 30% each year. Write an equation that represents this situation.
a)
y=5000(0.7)x
b)
y=30(5000)x
c)
y=5000(1.3)x
d)
y=5000xx
2.
A population of fish starts at 8,000 and decreases by 6% per year. What is the population of fish after 10 years?
a)
14327
b)
4309
c)
839
d)
7680
3.
Daniel’s Print Shop purchased a new printer for $35,000. Each year it depreciates at a rate of 5%. How much will the printer be worth in 8 years?
a)
$23,219.72
b)
$136.72
c)
$51,710.94
d)
$16,710.94
4.
You buy a new computer for $2100. The computer decreases by 50% annually. How much is it worth after 2 years.
a)
225
b)
325
c)
425
d)
525
5.
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?
Every year the population drops by 4.5%. What is the population after 3 years?
a)
1,069 people
b)
894 people
c)
816 people
d)
854 people
6.
The Country of Puerto has 3,370,000 people in it and is decreasing at a rate of 4.5%. Estimate the population after 40 years.
a)
534,275
b)
19,601,148
c)
1,350,756
d)
2,521,541
7.
a)
The graph represents an exponential growth situation.
b)
Eventually, the car will be worth exactly $0.
c)
The starting value of the car was $12,000.
d)
The range for the situation is y ≥ 0.
8.
An antibiotic is introduced into a colony of 12,000 bacteria during a laboratory experiment. The colony is decreasing by 14.9% per minute. Which function can be used to model the number of bacteria in the colony after x minutes?
a)
f(x) = 12000(1 + 14.9)x
b)
f(x) = 12000(1 - 14.9)x
c)
f(x) = 12000(1 + 0.149)x
d)
f(x) = 12000(1 - 0.149)x
9.
Which of the following is an example of exponential decay?
a)
y = 8(1.05)t
b)
y = .8(1.05)t
c)
y = 1.8(1.05)t
d)
y = 8(.95)t
10.
Is this exponential growth or decay?
a)
Growth
b)
Decay
100 %
