How long does it take you?

I'm very confused, personally I always thought I read pretty fast and it was fine but recently I've been hearing lots of people saying stuff like 'Lol I've read thousands of mangas' and 'yea I read 20 last night', I just thought they were exaggerating or whatever but then they actually show me their lists and which ones they're in the process of reading or haven't read yet and there are hundreds and hundreds, which I would understand if they'd been reading many years but that doesn't seem the case. (Ik there's a possibility they're lying about what they've read and whatnot, but I've seen more than a few posts about it.) Anyway, I was wondering, how long does it take y'all to read a manwha that has around 30 chapters? Thanks! (=・ω・=)