Doubling Time and Half Life Worksheet with Answer Key

What's on the worksheet

1. For each model, give the starting amount, say if it doubles or halves and give the doubling time or half-life.
   y = 35 \cdot 2^{t/9}y = 2400\left(\dfrac{1}{2}\right)^{t/20}y = 18 \cdot 4^{t/10}y = 500 \cdot 2^{-t/3}y = 72\left(\dfrac{1}{4}\right)^{t}
2. Word problem: how much phosphorus-32 was in the sample at the start.
3. Word problem: how fast the shares of a post grow in its first hours.
4. Word problem: players of a new online game doubling every 4 weeks.
5. Word problem: sunlight brightness halving with each 4 meters of lake depth.
6. Word problem: the half-life of an old messaging app's falling daily users.