Exponential growth and decay
Grade 9 Math Worksheet
Circle the best answer, or write your answer on the line.
Esme's school robotics club grows by 12% each year. 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?
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?
A science video starts with 250 yeast cells that grow 20% each hour. Ren watches. To the nearest whole number, how many cells are there after 4 hours?
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(0.15)^t
- y = 20(1.15)^t
- y = 20 + 3t
Luz shines 900 lux through layers of film, and each layer blocks 25% of the light reaching it. Which equation gives the amount y after t layers?
- y = 900(1.25)^t
- y = 900(0.75)^t
- y = 900(0.25)^t
Milo's bike club has 50 members and grows 8% each month. Which equation gives the amount y after t months?
- y = 50(0.08)^t
- y = 50 + 4t
- y = 50(1.08)^t