Chapter 4.1, Problem 1TU

TEST YOUR UNDESTANDING| FOR EXAMPLE $4.1$

Polonium- $210$ is another radioactive substance. To find next week’s amount of polonium- $210$, we multiply this week’s amount by $0.97$. Suppose there are initially $10$ grams of polonium- $210$. Find a formula that gives the amount $P$, in $\text{grams}$, of polonium- $210$ present after $t$ weeks. How long will it be before there are only $5\text{grams}$ remaining?