Exponential growth and decay
Grade 9 Math Worksheet
Circle the best answer, or write your answer on the line.
Each wash fades the dye in Jun's shirt by 6%. What number goes on each arrow of the growth table?
Kira's town has 2.5% more people each year. What number goes on each arrow of the growth table?
Each squeeze takes 30% of the water left in Luz's sponge. What number goes on each arrow of the growth table?
Milo's town has 4,500 people and grows 3% each year. To the nearest whole number, how many people live there after 5 years?
Pia shines 800 lux of light through 3 sheets of thick paper. Each sheet blocks 30% of the light reaching it. To the nearest whole lux, how much gets through?
Tala's water has 2000 specks per mL. A filter takes out 40% of the specks on each pass. How many specks per mL are left after 3 passes?
Zee's notes say the light through t layers of film is y = 1200(0.85)^t. By what percent does the light drop with each layer?
A used scooter's value is y = 240(0.97)^t after t months. Bo asks: by what percent does it drop each month?
A pond plant's area is y = 15(1.4)^t after t weeks. By what percent does Esme see it grow each week?
A fern patch in Kira's garden bed covers 20 square cm and grows 15% each week. Which equation gives the amount y after t weeks?
- y = 20(1.15)^t
- y = 20(0.15)^t
- y = 20 + 3t