yay 13/4 was on there!! And I must have misheard my friends on the other ones.

Time Signatures are pretty easy, the top number is the number of beats per measure.

the bottom number is what type of note constitutes one beat in that song...

There for 3/4 will have three beats per measure with a quarter note representing one of those three beats.

Of course you can rearrange it with the math so 6 8th notes is appropriate in 3/4 time.

I couldn't be bothered checking them all, but wikipedia said "Quiet" by The Smashing Pumpkins is partially in 13/4, but it just goes into 6/4 for a few bars and there's a 2/4 in there too. There's no 13/4, and even if it went into 6/4 then 7/4 that's not how a normal person would count it :P