Exponential Equations Growth and Decay Word Problems

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

• y=5000(1-0.3)^x
• y=30(5000)^x
• y=5000(1+0.3)^x
• y=5000x^x

Tags

CCSS.HSF.LE.A.2

The number of mosquitoes at the beginning of the summer was 4,000. The population of mosquitoes is expected to grow at a rate of 25% a month. How many mosquitoes will there be after 4 months?

• 9766
• 9006
• 9765
• 5433

Tags

CCSS.HSF.BF.A.2

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

Tags

CCSS.HSF.LE.A.2

What is a, the starting term, for the function: f(x) = 300(1.16)^x?

• 300
• 1.16
• .16
• x

Tags

CCSS.HSF.LE.B.5

What does the a in y=a(1+r)^t  represent?

• Time
• Rate
• Slope
• Initial Amount

Tags

CCSS.HSF-IF.C.8B

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

Tags

CCSS.HSF.BF.A.2

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?

• $23,219.72
• $136.72
• $51,710.94
• $16,710.94

Tags

CCSS.HSF.BF.A.2

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)

A city has a population of 21,517 based on a census taken in 1998. If the population is expected to grow by 11% annually, what will the population be in the year 2030?

• 606,900
• 517
• 492,573
• None of these

Tags

CCSS.HSF-LE.A.1C

Your 2 year investment of $5,300 earns 2.9% and is compounded annually.  What will your total return be?

• $5,304.46
• $5,611.86
• $5,613.28
• $8,819.73