An AM broadcast station operates at its maximum allowed

An AM broadcast station operates at its maximum allowed total of 100 kW with 90% modulation. The power in the intelligence part is—

Power in intelligence part, means we have to calculate the power in sideband.
Given that P_t = 100 kW
Now,

P_t = P_c		1 +	μ²
			2

100kW = P_c		1 +	0.9³
			2

or
P_c = 71.2kW
Now again,
P_t = P_c+sideband power
100 = 71.2+sideband power
or
sideband power = 100-71.2 = 28.8 kW.