Mastering Exponential Decay and Percent Decrease in 8th Grade

A car's value decreases by 15% each year. If the car is currently worth $20,000, what will its value be after one year?

• $17,000

• $18,000

• $15,000

• $19,000

A population of bacteria decreases by 30% every hour. If there are initially 1,000 bacteria, how many will remain after 2 hours?

• 490

• 600

• 800

• 700

A smartphone loses 20% of its value each year. If it was purchased for $600, what will its value be after 3 years?

• 240

• 480

• 360

• 307.2

A tree's height decreases by 10% each year due to disease. If the tree is currently 15 feet tall, what will its height be after 2 years?

• 12.15 feet

• 10.5 feet

• 14 feet

• 13.5 feet

A certain type of fish in a lake decreases in population by 25% each year. If there are 800 fish now, how many will be left after 3 years?

• 600

• 400

• 337

• 250

A company's revenue decreased by 12% last year. If the revenue was $500,000, what is the new revenue after the decrease?

• $480,000

• $500,000

• $460,000

• $440,000

A book's price is reduced by 18% during a sale. If the original price was $25, what is the sale price of the book?

• $22.00

• $18.50

• $20.50

• $21.00

A town's population is decreasing by 5% each year. If the current population is 10,000, what will the population be in 4 years?

• 9500

• 8146

• 7800

• 9000

A laptop's value depreciates by 22% each year. If it was bought for $1,200, what will its value be after 2 years?

• $800.00

• $960.00

• 729.12

• $1,000.00

A plant's growth rate decreases by 15% each month. If it grows 10 inches in the first month, how much will it grow in the second month?

• 6 inches

• 9 inches

• 8.5 inches

• 12 inches