However I am thinking of this question to be damn easy but still I'll not say as I am not getting it,
There are two radio nuclei $A$ and $B$. $A$ is $\alpha$ emitter and $B$ is $\beta$ emitter and their decay constant are in ratio $1:2$. What should be the number of atoms of $A$ and $B$ at time $t=0$, so that probability of getting $\alpha$ and $\beta$ particles are same at $t=0$.
So here how can the decay constant be dependent on number of atoms of $A$ and $B$ so that $\alpha$ and $\beta$ particle are in same ratio? I really need a right approach for this one.