Please help ?

2 Power ratio is often given in decibels (dB) Assume a signal loses of its power as it travels to the destination. What is the value of dB for this signal? Show your work. Briefly describe the wireless propagation problem 4-Assume the power of a signal at 75 meters is 300 mW what would be it power at 175 meters. 5- 10 channels each with a 50 KHz bandwidth, are to be multiplexed together. What is the minimum bandwidth of the link if there is a need for a guard band of 5 KHz between the channels to prevent interference