[tex]Dane:\\T =2 \ h\\t = 6 \ h\\Szukane:\\N(t) = ?\\\\\\N(t) = N_{o}\cdot(\frac{1}{2})^{\frac{t}{T}}\\\\N(t) = N_{o}\cdot(\frac{1}{2})^{\frac{6h}{2h}}\\\\N(t) = N_{o}\cdot(\frac{1}{2})^{3}\\\\\boxed{N(t) = \frac{1}{8}N_{o}}\\\\\underline{Odp. \ a)}[/tex]