1. d 2. c 3. b 4. c 5. d 6. c 7. 512m or 500m or 0.5km or ((2*10^8 * 5.12*10^-6) / 2) 8. 0.512 microseconds or 512 nanoseconds or 512 bits 9. c 10. b 11. c 12. a 13. b 14. 35.584Mbps or 35Mbps or 35000000 bps or (6*log(60+1)/log(2)) 15. 8 16. 278, or ~250 or (1000 - 1000*-(0.8*log(0.8)/log(2) + 0.2*log(0.2)/log(2))) 17. -0.96910 or -1 or (10 * log ( 80.0 / 100.0 ) /log(10)) 18. c 19. d 20. c