please help as soon as possible

1. Five channels, each with a 100-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 10 kHz between the channels to prevent interference? Calculate the effective bandwidth. 2. A multiplexer combines twelve 100-kbps channels using a time slot of 8 bits. Calculate the frame rate and the frame duration? 3. 100 resource blocks everyone has a frequency band of 180 kHz. Each resource block is divided to 24 x 7 kHz subcarriers, a. Calculate the cyclic prefix for each subcarrier, b. Calculate the data rate for each OFDM frame if 64-QAM is used. C. For 20 frames/second/resource-block, calculate overall system data rate.