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 10^$$-$$x W. The value of x is ________.

[Gain in $$dB = 10{\log _{10}}\left( {{{{P_o}} \over {{P_i}}}} \right)$$]

An audio signal v_m = 20 sin 2$$\pi$$(1500t) amplitude modulates a carrier v_c = 80 sin 2$$\pi$$(100,000t).

The value of percent modulation is _________.