The time of reverberation of a room A is one second. What will be...

Reverberation Time $$T=\frac{0 \cdot 61 V}{A S}$$ Where $V=$ Volume of room in cubic metre $A=$ Average coefficient of the room $S=$ Total surface area of room Then, \begin{aligned} & T \propto \frac{V}{S} \\ & \text{ or } \frac{T_1}{T_2}=\left(\frac{V_1}{V_2}\right)\left(\frac{S_2}{S_1}\right)=\left(\frac{V}{8 V}\right)\left(\frac{45}{5}\right) \\ & =\frac{1}{2} \\ & \therefore T_2=2 T_1=2 \times 1=2 \mathrm{sec} . \\ & \left(\because T_1=1 \mathrm{sec}\right) \\ & \end{aligned}