Exponential Functions: Growth and Decay Challenges for 8th Grade

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

• 200

• 100

• 400

• 800

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

• $14,450

• $18,000

• $12,000

• $16,000

A bacteria culture grows exponentially. If it starts with 200 bacteria and doubles every 4 hours, how many bacteria will there be after 12 hours?

• 1600

• 3200

• 400

• 800

A bank account earns 5% interest compounded annually. If you deposit $1,000, how much will you have after 3 years?

• 1200.00

• 1100.50

• 1305.25

• 1157.63

A tree's height increases by 10% each year. If it is currently 4 meters tall, what will its height be in 5 years?

• 8.00 meters

• 6.44 meters

• 7.20 meters

• 5.00 meters

A radioactive substance decays at a rate of 20% per hour. If you start with 100 grams, how much will remain after 3 hours?

• 75 grams

• 51.2 grams

• 60 grams

• 40 grams

A certain species of fish decreases in population by 25% each year. If there are 800 fish now, how many will be left after 2 years?

• 600

• 200

• 300

• 450

A savings account has an initial deposit of $500 and earns 3% interest compounded annually. How much will be in the account after 4 years?

• 562.75

• 575.50

• 600.00

• 550.00

A certain type of mold grows at a rate of 30% per day. If you start with 10 grams, how much will you have after 3 days?

• 50 grams

• 21.97 grams

• 15 grams

• 30 grams

A tree loses 40% of its leaves each autumn. If it starts with 1,000 leaves, how many leaves will it have left after one autumn?

• 800

• 200

• 400

• 600