Okay, so first, let us say he cannot see the keys, then he would have a 2/5 chance on the first try and a 2/5 chance on the second try for a probability of 4/25...correct?

why did you say that he had a 2/5 chance on the first then a (3/5)(2/5) chance on the second try...this i do not understand?

Then, second, if he keeps the first key he tries separated from the other keys, he would have a 2/5 chance on the first try and a 2/4 chance on the second try for a probability of 4/20...correct?

sorry, this stuff is new to me, thanks for helping