There are tons of threads about Simplex (use the search)....I interviewed for them a few months back and I never really followed up with them (but heres some info i remember from the interviews):
They have two firms, one that is their prop group (you get paid a small salary + bonus'....from what i remember, they just make markets on options, trading firm capital), and they also have a individual account/prop group (you can deposit some cash and get leverage and day trade the options yourself). They got groups/traders from all different backgrounds....a lot of ex-CBOE market makers and also some recent grads with less than 10k in their accounts. If you deposit money and do the prop route, they do offer some classes/training and you trade through a Think or Swim platform/clearing.
As for their logic test....it was a 20 minute test plus some "mental math" and problem solving questions during the interview. I've been on a lot of "junior trader" interviews (and i've already worked on the floor) and I found their test to be more difficult than most others.
