Just one, but they get extra credits for it
Zero. They just keep praising and negging it, and then get upset when it doesn't screw.
2...and don't ask me how they got in there. (My 87 year old grandma just told me this one)
It only takes one, but we weren't able to get the work done in 1 term because we inherited a really bad situation from the prior administration.
One to hold the bulb, and the rest to screw the whole world.