Growth and Decay Word Problems

1. Vanessa invested $2,500 into an account that will increase in value by 3.5% each year. Write an exponential function to model this situation, then find the value of the investment after 20 years.

• f(t)=2500(1.035)^t
• $4974.47
• $5125.84
• f(t) = 2500(20)^t
• f(t)=20(2500)^t

2. The average price of a movie ticket in 1990 was $4.22. Since then, the price has increased by approximately 3.1% each year. Write an exponential function to model this situation, then find the price of a ticket in 2016.

• $9.33
• f(t) = 1.031(4.22)^t
• $8.85
• $10.12
• f(t) = 4.22(1.031)^t

3. A virus has infected 400 people in the town and is spreading to 25% more people each day. Write an exponential function to model this situation, then find the number of people that will be infected in 10 days.

• 3725
• F(t) = 400(1.25)^t
• 3576
• 3462
• f(t) = 1.25(400)^t

4. The population of a small town was 10,800 in 2002. Since then, the population has decreased at a rate of 2.5% each year. Write an exponential function to model the situation, then find then population of the town in 2020.

• f(t) = 10800(.975)^t
• 6847
• 6374
• f(t) = .975(10800)^t
• f(t)=.975(2002)^t

5. Manny bought a brand new car in 2012 for $28,750. If the car depreciates by 12% each year, write an exponential function to model the situation, then find the value of the car in 2018.

• $13,351.62
• f(t)=28750(.88)^t
• f(t) = .88(28750)^t
• $12,894.36
• f(t)=1.88(28750)^t

6. Anisha invested $8,000 in an account that earns 10% interest. How much money will she have in 15 years if the interest is compounded quarterly?

• $35,198.32
• $33,873.85
• $10,488.20
• $34, 765.76

7. A realtor took $32,500 made on the sale of a home and placed it in a new account that earns 6% compounded annually. Find the total amount in the account after 5 years.

• $43,248.93
• $41,976.24
• $43,492.33
• $42,826.41

8. Scott invested $1600 into a retirement account that earns 2.4% interest compounded monthly. What will the balance of the account be after 30 years?

• $4,278.35
• $3,284.73
• $3,569.16
• $4,578.29

Given the following set of points, (3,1) and (4,3) write an equation in slope-intercept form.

• y=4x-5
• y=2x-5
• y=-4x-5
• y=-5x+4

Given the following set of points, (0, -4) and (-3, 0) write an equation in slope-intercept form.

• y=(4/3)x-4
• y=-4x-(4/3)
• y=4x-(4/3)
• y= -(4/3)x-4