Skills · Functions · Exponential Functions

Evaluating growth and decay

Printable practice with an answer key the engine computes, at three levels, in as many versions as you need.

Problem types

• doubling, a(2)ᵗ: y = 50(2)^t when t = 3
• halving, a(1/2)ᵗ: y = 96((1/2))^t when t = 3
• growth by a percent: y = 500(1.04)^t when t = 2
• decay by a percent: y = 1,000(0.8)^t when t = 2
• a percent over three steps: y = 800(1.05)^t when t = 3

Sample Sheet · Level 1

1. Cells in a dish: y = 15(2)^t. Find y when t = 3.
2. A dose of medicine: y = 224(12)^t. Find y when t = 4.
3. A dose of medicine: y = 88(12)^t. Find y when t = 3.
4. Cells in a dish: y = 5(2)^t. Find y when t = 3.
5. y = 7(2)^t. Find y when t = 4.
6. y = 12(2)^t. Find y when t = 4.
7. y = 20(12)^t. Find y when t = 2.
8. A ball’s bounce height: y = 28(12)^t. Find y when t = 2.

Answer key

1. 120
2. 14
3. 11
4. 40
5. 112
6. 192
7. 5
8. 7

Sample Sheet · Level 3

1. y = 600(1.1)^t. Find y when t = 2.
2. A car’s value: y = 17,500(0.8)^t. Find y when t = 3.
3. A savings account: y = 2,000(1.05)^t. Find y when t = 3.
4. y = 28(2)^t. Find y when t = 4.
5. y = 20,000(0.75)^t. Find y when t = 2.
6. A ball’s bounce height: y = 32(12)^t. Find y when t = 2.
7. A savings account: y = 4,500(1.04)^t. Find y when t = 2.
8. A bacteria count: y = 35(2)^t. Find y when t = 3.

Answer key

1. 726
2. $8,960.00
3. $2,315.25
4. 448
5. 11,250
6. 8
7. $4,867.20
8. 280

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