Real-World Exponential Growth & Decay Word Problems

A population of rabbits doubles every year. If there are currently 50 rabbits, how many will there be in 3 years? Identify if this is growth or decay.

• 400 rabbits, this is growth.

• 100 rabbits, this is decay.

• 50 rabbits, this is decay.

• 200 rabbits, this is growth.

A car's value decreases by 20% each year. If the car is worth $15,000 now, what will its value be in 2 years? Is this an example of growth or decay?

• $10,800. This is an example of growth.

• $9,600. This is an example of decay.

• $12,000. This is an example of growth.

• $7,500. This is an example of decay.

A bank account earns 5% interest compounded annually. If you deposit $1,000, how much will you have after 4 years? Determine if this is growth or decay.

• $1,000.00

• $1,050.00

• $1,215.51

• $1,100.00

A bacteria culture triples in size every hour. If you start with 10 bacteria, how many will there be after 5 hours? Classify this as growth or decay.

• 2000

• 1000

• 1500

• 2430

A tree's height decreases by 10% each year due to disease. If it is currently 40 feet tall, what will its height be in 3 years? Identify the type of change occurring.

• 35 feet

• 29.16 feet

• 32 feet

• 25 feet

A savings account has a balance of $2,000 and earns 3% interest compounded annually. What will the balance be after 5 years? Is this growth or decay?

• $1800, growth

• $2500, decay

• $2318.55, growth

• $2000, decay

A certain species of fish in a lake decreases by 15% each year due to overfishing. If there are currently 1,200 fish, how many will be left after 4 years? Classify this situation.

• 500

• 626

• 900

• 800

A smartphone loses 25% of its value each year. If it was purchased for $800, what will its value be after 3 years? Identify if this is growth or decay.

• $250.00

• $400.00

• $600.00

• $337.50

A population of trees in a forest increases by 10% each year. If there are currently 1,000 trees, how many will there be in 2 years? Determine if this is growth or decay.

• 900 trees, this is decay.

• 1100 trees, this is growth.

• 1300 trees, this is decay.

• 1210 trees, this is growth.

A radioactive substance decays by half every 5 years. If you start with 80 grams, how much will remain after 15 years? Classify this as growth or decay.

• 15 grams

• 5 grams

• 20 grams

• 10 grams