Mastering Exponential Functions and Growth Rates in 8th Grade

A bacteria culture doubles in size every 3 hours. If there are initially 500 bacteria, how many will there be after 9 hours?

• 3000

• 2000

• 1000

• 4000

A tree grows at a rate of 5% per year. If the tree is currently 2 meters tall, what will its height be after 4 years?

• 2.80 meters

• 2.00 meters

• 2.43 meters

• 2.10 meters

A population of rabbits increases by 20% each month. If there are 150 rabbits at the start, how many will there be after 3 months?

• 259

• 225

• 300

• 180

A savings account earns 6% interest compounded annually. If you deposit $1,000, how much will you have in the account after 5 years?

• 1200.00

• 1005.00

• 1500.50

• 1338.23

A viral video is viewed by 1,000 people on the first day and the views double each subsequent day. How many views will it have on the 7th day?

• 128000

• 64000

• 256000

• 32000

A certain species of fish in a lake grows at a rate of 15% per year. If there are currently 200 fish, how many will there be after 2 years?

• 265

• 150

• 300

• 230

A smartphone app has 10,000 downloads and is growing at a rate of 25% per month. How many downloads will it have after 2 months?

• 14000

• 12000

• 20000

• 15625

A population of a city is 50,000 and is growing at a rate of 3% per year. What will the population be in 5 years?

• 55000

• 50000

• 57964

• 60000

A certain type of investment grows at an exponential rate of 8% per year. If you invest $2,000, how much will it be worth after 10 years?

• 3500.00

• 4317.84

• 5000.00

• 6000.50

A viral infection spreads in a community, doubling the number of infected individuals every week. If there are 30 infected individuals initially, how many will there be after 4 weeks?

• 360

• 480

• 600

• 240