how to calculate this EIRP? and some related questions?

Question 1a
Find the EIRP needed for a LOS FM station knowing the following parameters:
G/T at the the receiver is 12dB, data rate is 512 Kbps, distance between Tx and Rx is 30km. working frequency is 9GHz, and C/N ≥ 12dB

Question 1b
Find the EIRP needed for an Earth Station (ES) knowing the following parameters:
G/T of the Satelite Station (SS) is 12dB, Bandwidth is 24MHz. working frequency is 4GHz, and C/N ≥ 12dB (it would be a GeoStationary SS)

Question 1c
Find the value of the parameter G/T of a GeoStationary Satelite Station (GSSS) knowing the following parameters, EIRP of Earth Station (ES) is 17dB, data rate is 64Kbps, S/N ≥ 12dB and working frequency is 14.1 Ghz

Question 2:
What is the relationship between the B (bandwidth of channel) and R (data rate). I mean, if they give us the parameter R, how can you find B?

Question 3:
If we know the type of modulation, can we find the bandwidth needed to transmit the data. e.g. QPSK --> B = 64K --> this is right or wrong?


Thank you in advance!