Exploring Exponential Growth and Decay in Real Life

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

• 1000

• 4000

• 2000

• 3000

A car's value decreases by half every 5 years. If the car is worth $20,000 now, what will its value be in 15 years?

• $1,000

• $2,500

• $5,000

• $10,000

A tree grows at a rate of tripling its height every year. If it starts at 2 feet tall, how tall will it be after 3 years?

• 36 feet

• 6 feet

• 54 feet

• 18 feet

A population of fish in a lake triples every year. If there are 200 fish now, how many will there be in 2 years?

• 400

• 1800

• 600

• 1200

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

• 10 grams

• 40 grams

• 5 grams

• 20 grams

A savings account doubles its balance every 4 years. If you deposit $1,000, how much will you have after 12 years?

• 16000

• 8000

• 2000

• 4000

A certain species of plant doubles its number every month. If you start with 10 plants, how many will you have after 6 months?

• 320

• 640

• 80

• 20

A smartphone loses 30% of its value each year. If it is worth $600 now, what will its value be after 2 years?

• 360

• 480

• 294

• 420

A population of rabbits triples every year. If there are 50 rabbits now, how many will there be in 4 years?

• 1000

• 4050

• 1500

• 200

A certain type of mold doubles in size every 2 days. If you start with 5 grams, how much will you have after 10 days?

• 160 grams

• 80 grams

• 200 grams

• 40 grams