Exponential Growth & Decay: Real-World Challenges

A bacteria culture doubles in size every 3 hours. If the initial population is 500, how many bacteria will there be after 12 hours?

• 10000

• 8000

• 4000

• 2000

A radioactive substance has a half-life of 5 years. If you start with 80 grams, how much will remain after 15 years?

• 40 grams

• 10 grams

• 20 grams

• 5 grams

A certain investment doubles in value every 10 years. If you invest $1,000, how much will it be worth after 30 years?

• $8,000

• $16,000

• $2,000

• $4,000

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

• 9.60 feet

• 12.17 feet

• 14.00 feet

• 10.40 feet

A certain type of bacteria decays at a rate of 25% per hour. If you start with 200 grams, how much will remain after 4 hours?

• 50 grams

• 100 grams

• 63.28125 grams

• 150 grams

A population of rabbits increases by 50% every month. If there are currently 200 rabbits, how many will there be after 6 months?

• 2280

• 1500

• 3000

• 1200

A certain isotope has a half-life of 3 days. If you have 64 mg of the isotope, how much will be left after 9 days?

• 8 mg

• 16 mg

• 4 mg

• 32 mg

A car's value depreciates by 20% each year. If the car is worth $20,000 now, what will its value be after 3 years?

• $8,000

• $10,240

• $15,000

• $12,500

A certain investment grows exponentially, doubling every 5 years. If you invest $2,000, how much will it be worth after 15 years?

• $8,000

• $4,000

• $16,000

• $32,000

A population of fish in a lake decreases by 10% each year due to overfishing. If there are currently 1,000 fish, how many will be left after 4 years?

• 500

• 900

• 800

• 656