Understanding Exponential Growth and Decay in Real Life

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

• 4000

• 1000

• 2000

• 3000

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?

• $18,000

• $16,000

• $14,450

• $12,000

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?

• 15 feet

• 11 feet

• 10.5 feet

• 12.16 feet

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

• 1216.65

• 1000.00

• 1500.00

• 1100.00

A certain radioactive substance decays to half its amount every 10 years. If you start with 80 grams, how much will remain after 30 years?

• 20 grams

• 5 grams

• 10 grams

• 40 grams

A population of rabbits increases by 25% each year. If there are 200 rabbits now, how many will there be in 3 years?

• 391

• 250

• 300

• 450

A smartphone loses 20% of its value each year. If it costs $800 now, what will its value be after 3 years?

• $720.00

• $512.00

• $409.60

• $640.00

A savings account has an initial deposit of $500 and earns 6% interest compounded annually. How much will be in the account after 3 years?

• 595.51

• 550.00

• 575.00

• 600.00

A certain species of fish in a lake decreases by 10% each year due to pollution. If there are currently 1,000 fish, how many will be left after 2 years?

• 810

• 900

• 500

• 750

A tree's height increases by 8% each year. If it is currently 15 feet tall, what will its height be after 2 years?

• 16.5 feet

• 17.496 feet

• 18 feet

• 15.5 feet