This is going to be a short post about my current observation on questions complexity. Well, now I can probable draw it like this:
CR < RC < PS = DS
I found CR to be a little bit more time-consuming then RC, but I think this is normal, as you have a separate block of text in each question instead of (bigger) one, but for 3-5 questions. It requires to change the topic more often and it can be a valid reason for many careless errors.