\(\frac{{4 - 3}}{{6 - 4}} = \lambda \,\, \Rightarrow \,\,\lambda  = \frac{1}{2}\)

\({T_{1/2}} = \frac{{0.693}}{\lambda } = 2 \times 0.693\,\, \Rightarrow \,{T_{1/2}} = 1.386\,\)

આપેલ  \(\,t\,\, = \,\,4.16\,\) વર્ષ \( \approx \,\,3{T_{1/2}}\,\)

\(\therefore\)  અવિભજીત અંશ \({\text{ }} = \frac{1}{{{2^3}}} = \frac{1}{8} = \frac{1}{p}\,\,\)    (\(Q\) માં આપેલ સંખ્યા)  

\(\, \Rightarrow \,\,{\text{p}}\,\, = \,\,{\text{8}}{\text{.}}\)