Exponential Growth & Decay: Half-Life & Doubling Time Quiz

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

• 5 grams

• 20 grams

• 10 grams

A population of bacteria doubles every 3 hours. If you start with 500 bacteria, how many will there be after 12 hours?

• 8000

• 1000

• 16000

• 4000

A certain type of tree grows at a rate of 10% per year. If the tree is currently 2 meters tall, how tall will it be in 5 years?

• 2.5 meters

• 4.0 meters

• 5.0 meters

• 3.22 meters

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

• $15,000

• $8,000

• $10,240

• $12,500

A culture of yeast doubles in size every 4 hours. If you have 250 grams of yeast, how much will you have after 16 hours?

• 500 grams

• 1000 grams

• 2000 grams

• 4000 grams

A certain medication has a half-life of 8 hours. If a patient takes 200 mg, how much of the medication will be in their system after 24 hours?

• 25 mg

• 50 mg

• 100 mg

• 10 mg

A bank account earns 5% interest compounded annually. If you deposit $1,000, how much will you have after 10 years?

• 1500.00

• 1200.50

• 2000.00

• 1628.89

A certain species of fish in a lake doubles its population every year. If there are currently 1,000 fish, how many will there be in 5 years?

• 64000

• 32000

• 10000

• 5000

A radioactive isotope has a half-life of 10 days. If you start with 160 mg, how much will remain after 30 days?

• 80 mg

• 40 mg

• 20 mg

• 10 mg

A tree grows at a rate of 15% per year. If it is currently 3 meters tall, how tall will it be in 4 years?

• 6.0 meters

• 7.2 meters

• 4.5 meters

• 5.25 meters