Consider the following reaction, the rate expression of which is given below $$\begin{aligned} & \mathrm{A}+\mathrm{B} \rightarrow \mathrm{C} \\ & \text { rate }=\mathrm{k}[\mathrm{A}]^{1 / 2}[\mathrm{~B}]^{1 / 2} \end{aligned}$$ The reaction is initiated by taking $1 \mathrm{~M}$ concentration of $\mathrm{A}$ and $\mathrm{B}$ each. If the rate constant $(\mathrm{k})$ is $4.6 \times 10^{-2} \mathrm{~s}^{-1}$, then the time taken for $\mathrm{A}$ to become $0.1 \mathrm{~M}$ is $\underline{\hspace{2cm}}$ sec. (nearest integer)