7th Grade Quiz: Exponential Growth and Decay Challenges

A population of rabbits doubles every year. If there are 50 rabbits now, how many will there be in 3 years?

• 200 rabbits

• 800 rabbits

• 100 rabbits

• 400 rabbits

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

• $16,000

• $18,000

• $14,450

• $12,000

A bacteria culture grows exponentially. If it starts with 100 bacteria and triples every hour, how many bacteria will there be after 4 hours?

• 10000

• 2400

• 5000

• 8100

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

• 12.76 feet

• 10 feet

• 8 feet

• 15 feet

A bank account earns 4% interest compounded annually. If you deposit $1,000, how much will you have in the account after 3 years?

• 1000.00

• 1100.00

• 1124.86

• 1200.00

A certain radioactive substance decays at a rate of 10% per hour. If you start with 200 grams, how much will remain after 3 hours?

• 145.8 grams

• 200 grams

• 180 grams

• 120 grams

A population of fish in a lake decreases by 20% each year due to overfishing. If there are currently 1,000 fish, how many will be left after 2 years?

• 800

• 500

• 720

• 640

A savings account has an initial deposit of $500 and earns 6% interest compounded annually. How much will be in the account after 4 years?

• 600.00

• 700.00

• 500.00

• 631.24

A tree's height increases by 3 inches each year. If it is currently 15 inches tall, what will its height be in 6 years?

• 30 inches

• 36 inches

• 27 inches

• 33 inches

A certain type of mold grows at a rate of 50% every day. If you start with 10 grams, how much will you have after 3 days?

• 33.75 grams

• 25 grams

• 50 grams

• 40 grams