In a reaction A+B → C, initial concentrations of A and B are related as [A]_0=8[B]_0. The half lives of A and B are 10 min and 40 min, respectively.…

In a reaction $\displaystyle A+B \rightarrow C$, initial concentrations of $\displaystyle A$ and $\displaystyle B$ are related as $\displaystyle [A]_0=8[B]_0$. The half lives of A and B are $\displaystyle 10$ min and $\displaystyle 40$ min, respectively. If they start to disappear at the same time, both following first order kinetics, after how much time will the concentration of both the reactants be same ?