We're not here to judge you about your personal life choices but it explains your handle and new picture.
No clue. It is a really odd amount, now that you mention it.
Forgot to say why. I am trying to decide how big my Pumador will need to be. I don't have a lot of space and am wondering, if I choose crockery, what size crock I would need.
Well, I do know that the standard pack of seven cakes/bings weighs 5 "jin." I understand how 7 is a special number in Chinese culture, so if you want 7 bing in a pack, but I don't know why the whole thing has to weigh 5 jin, rather than some other non-fractional number of jin.