Answer:
The amount present in a sample of 401 grams after 25 years is [tex]180\ g[/tex]
Step-by-step explanation:
we have
A(t) -----> the amount, in grams, of polonium 210 present in a given sample
t -----> the time in years
[tex]A(t)=401e^{-0.032t}[/tex]
we know that
To find out the amount present in a sample of 401 grams after 25 years, substitute the value of t=25 years in the equation and solve for A(t)
For t=25 years
[tex]A(25)=401e^{-0.032(25)}[/tex]
[tex]A(25)=180.18\ g[/tex]