Problem /solution related to AM waves

An amplitude modulated waveform has the form x1((t)= 10[1+0.5 cos (2000*pi*t)+ 0.5 cos (4000*pi*t)] cos(20000*pi*t). determine the followings.

i)                    Sketch the amplitude spectrum of x(t)

ii)                   Find the average power content of each spectral component including the carrier

iii)                 Modulation index