Solving Exponential Growth and Decay Problems

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

• 10000

• 2000

• 4000

• 8000

The value of a car decreases exponentially. If a car is worth $20,000 and loses 15% of its value each year, what will its value be after 3 years?

• $15,000

• $10,000

• $18,000

• $12,282.50

A certain investment grows exponentially at a rate of 5% per year. If you invest $1,000, how much will it be worth after 10 years?

• 1628.89

• 1200.50

• 2000.00

• 1500.00

A tree grows at an exponential rate, increasing its height by 20% each year. If the tree is currently 2 meters tall, what will its height be after 5 years?

• 6.00 meters

• 5.00 meters

• 3.00 meters

• 4.98 meters

The number of users on a social media platform increases exponentially. If there are currently 1,000 users and the number doubles every month, how many users will there be in 6 months?

• 64000

• 8000

• 128000

• 32000

A radioactive substance decays exponentially. If you start with 80 grams and it decays to 25 grams in 10 years, what is the half-life of the substance?

• 5.5 years

• 10 years

• 3 years

• 8 years

A certain species of fish in a lake is known to double its population every year. If there are currently 200 fish, how many will there be in 4 years?

• 800

• 1600

• 2400

• 3200

A bank offers an account that compounds interest exponentially. If you deposit $500 at an interest rate of 4% compounded annually, how much will you have after 5 years?

• 500.00

• 520.00

• 640.00

• 608.33

A certain type of mold grows exponentially. If a colony starts with 50 spores and doubles every 2 days, how many spores will there be after 10 days?

• 400

• 1600

• 800

• 3200

A smartphone's battery life decreases exponentially. If it starts at 100% and loses 10% of its charge every hour, what will the battery percentage be after 5 hours?

• 45%

• 80%

• 70%

• 59.05%