A signal of 0.1 kW is transmitted in a cable. The attenuation of cable is -5 dB per km and cable length is 20 km. The power received at receiver is…

A signal of $\displaystyle 0.1$ kW is transmitted in a cable. The attenuation of cable is -$\displaystyle 5$ dB per km and cable length is $\displaystyle 20$ km. The power received at receiver is $\displaystyle 10^{-x} \mathrm{~W}$. The value of $\displaystyle x$ is \_\_\_\_. [Gain in $\displaystyle \mathrm{dB}=10 \log _{10}\left(\frac{\mathrm{P}_{\mathrm{o}}}{\mathrm{P}_i}\right)$ ]