VHF are the basic TV air channels, which are 2,3,4,5,6,7,8,9,10,11,12,13. Two and 13 are often PBS channels. There was originally a 1, but that frequency was too close to some other frequency in use, so it was dropped. By the way, all the FM radio channels are tucked in between channel 6 and 7.
VHF stands for "Very High Freqency." UHF, the channels from 14 to 83, stands for "Ultra High Frequency."
I decided to try it again. Unfortunately they give you the same questions! Anyway, the second time around I got 24 (missed the no smoking line angle), but that's not accurate at all because the first time when I did it, they gave me the answers to the questions I had missed.