Exponential Equations: Find the Unknown Growth Rates

A bacteria culture doubles in size every hour. If the culture starts with 5 bacteria, how many will there be after x hours if there are 320 bacteria?

• 4 hours

• 8 hours

• 10 hours

• 6 hours

A car's value decreases by 20% each year. If the car is currently worth $12,000, what will its value be after x years if it is worth $3,072?

• 8 years

• 5 years

• 6 years

• 7 years

A tree grows at a rate of 1.5 times its height each year. If a tree is currently 2 meters tall, how tall will it be after x years if it reaches 16 meters?

• 3 years

• 10 years

• 5 years

• 7 years

A population of fish in a lake triples every year. If there are currently 50 fish, how many will there be after x years if the population reaches 1,200 fish?

• 2 years

• 4 years

• 1 year

• 3 years

A savings account earns interest at a rate of 5% compounded annually. If you start with $1,000, how much will you have after x years if the account grows to $1,276.28?

• 7 years

• 3 years

• 10 years

• 5 years

A certain species of plant grows exponentially. If it starts with 10 plants and grows to 80 plants in x weeks, how many weeks did it take?

• 5 weeks

• 2 weeks

• 3 weeks

• 10 weeks

A viral video gets 4 times as many views each day. If it has 200 views today, how many views will it have after x days if it reaches 12,800 views?

• 2 days

• 5 days

• 10 days

• 3 days

A population of rabbits doubles every month. If there are currently 30 rabbits, how many will there be after x months if the population reaches 480 rabbits?

• 10 months

• 4 months

• 2 months

• 6 months

A certain investment grows at a rate of 10% per year. If you invest $500, how much will it be worth after x years if it grows to $1,348.85?

• 6.5 years

• 5 years

• 7 years

• 8 years