Depends on where you get them from, some site say to have 90% some sites say the guarantee 100.
I grew some feminized white widow i had 1 male out of 10, on a side not though, I didnt actually like the plants and thought that they grew differently because they were fem seeds, either that or they werent real widow
. either way, i just stick to nirvana regular now.
When I have completely mastered the art of cloning i wont bother with any seeds at all as I have more than enough strains.
Although there are still pleanty out there that i would love to grow.