Exponential Growth & Decay: Real-World Challenges

A bacteria culture doubles in size every 3 hours. If there are initially 500 bacteria, how many will there be after 9 hours?

• 3000

• 2000

• 4000

• 1000

A car's value decreases by 15% each year. If the car is worth $20,000 now, what will its value be after 2 years?

• $14,450

• $18,000

• $12,000

• $16,000

A population of rabbits decreases by 10% each month. If there are 200 rabbits at the start, how many will be left after 6 months?

• 80

• 120

• 150

• 106

A tree grows at a rate of 5% per year. If it is currently 10 feet tall, how tall will it be after 4 years?

• 8 feet

• 15 feet

• 12.16 feet

• 10.5 feet

A radioactive substance decays by 25% every year. If you start with 80 grams, how much will remain after 3 years?

• 33.75 grams

• 20 grams

• 40 grams

• 50 grams

A savings account earns 4% interest compounded annually. If you deposit $1,000, how much will you have after 5 years?

• 1000.00

• 1100.00

• 1216.65

• 1300.00

A certain species of fish is decreasing in population by 20% each year. If there are 1,000 fish now, how many will be left after 3 years?

• 640

• 512

• 800

• 400

A tree's height is modeled by the function h(t) = 10(1.05)^t, where t is the number of years. What will be the height of the tree after 5 years?

• 15.50

• 12.76

• 8.25

• 10.00

A car depreciates in value according to the function V(t) = 20000(0.85)^t, where t is the number of years. What will the value of the car be after 4 years?

• 10440.13

• 12000.00

• 9500.50

• 15000.75

A certain type of mold grows exponentially. If it starts with 50 spores and doubles every 2 days, how many spores will there be after 10 days?

• 400

• 800

• 2000

• 1600