Question

1. (3) how long is 5.25 half - lives for pennium? 6 = 97.14 ( 1/2 ) 5.25

Explanation:

Step1: Identify the operation

We need to find the total time for 5.25 half - lives. If we assume the time of one half - life is \(t = 18.5\) (it seems the original work was dividing by 18.5 to get 97.14, but the problem is incomplete without knowing the time of one half - life. Let's assume one half - life is 1 unit for simplicity of showing the process). We multiply the number of half - lives by the time of one half - life.
\(5.25\times1 = 5.25\) (in units of half - life time)

Answer:

If the time of one half - life is 1 unit, the time for 5.25 half - lives is 5.25 units. If the actual time of one half - life is \(t\) (say \(t = 18.5\) as hinted by the incorrect work), then the time is \(5.25t\). Without knowing the actual value of one half - life time, we can only say the answer is \(5.25\) times the time of one half - life.