Exponential Growth and Decay: Real-World Applications

A bacteria culture doubles in size every 3 hours. If the initial population is 500, how many bacteria will there be after 9 hours?

• 1000

• 3000

• 2000

• 4000

A car's value decreases by 20% each year. If the car is currently worth $15,000, what will its value be after 3 years?

• $7,680

• $10,000

• $5,000

• $12,000

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

• 10.5 feet

• 12.16 feet

• 15 feet

• 11 feet

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

• 10 grams

• 5 grams

• 20 grams

• 40 grams

A certain type of fish population decreases by 10% each year due to overfishing. If the current population is 1,200, what will the population be after 2 years?

• 972

• 1,000

• 1,080

• 1,200

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

• 1100.00

• 1500.00

• 1000.00

• 1216.65

A smartphone loses 25% of its value each year. If it was purchased for $800, what will its value be after 2 years?

• $450

• $500

• $600

• $300

A certain species of plant grows exponentially. If it covers 2 square meters today and doubles in area every week, how much area will it cover in 4 weeks?

• 32 square meters

• 16 square meters

• 8 square meters

• 64 square meters

A population of rabbits decreases by 15% each year. If there are currently 500 rabbits, how many will there be after 3 years?

• 400

• 250

• 350

• 307

A scientist observes that a certain chemical decays exponentially. If the initial amount is 100 grams and it decays to 25 grams in 6 hours, what is the decay rate per hour?

• 0.100

• 0.150

• 0.231

• 0.500