Quiz on Growth and Decay

Write the equation for doubling an amount for 30 days ,

starting with a penny and where y represents dollars.

Which of the following functions shows an initial amount of $150 and an increase of 3.5% each year?

• y = 150(35)^x

• y = 15(1.035)^x

• y = 150(1.035)^x

• y = 35(1.50)^x

A population of fish starts at 6,000 and decreases by 8% per year. What is the population of fish after 10 years?

• 48000

• 4309
• 6080

• 2606

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

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

• Time
• Rate
• Slope
• Initial Amount

Daniel’s Print Shop purchased a new printer for $35,000. Each year it depreciates at a rate of 7%. How much will the printer be worth in 8 years?

• $23,219.72
• $136.72
• 19585.36

• $16,710.94

Semi-Annually means how many times a year?

• 4 
• 2
• 1

Olivia would like to buy some new furniture for her home. She decides to buy the furniture on credit with 8.0% interest compounded quarterly. If she spent $7,400, how much total will she have paid after 8 years.

• $13,945.60

• $15,683.28
• $15,927.56
• $16,109.05

Change 6.75% to a decimal.

• 67.5
• .675
• 675
• .0675

You invest $400 for 5 years at an interest rate of 4.29% each year. Which equation models this?

• y=400(1 - 0.0429)⁵

• y=400(1+.0429)⁵

• y=400(1+ 4.29)⁵

• y=400e^0.049*5