I am sure last year it was 90 seconds per question and there were four or five asked.This has been omitted from the invite. Could mean that there isn’t even a time limit, they are already giving us 3 attempts per question.
I think maybe the question showed for approx 30 seconds on the screen and then you had 90 seconds to answer. There also wasn't a running clock between each question, so you could start the next question when you pressed the button.
You had 3 x attempts per question (3 in total, not 4) and then your recent attempt would be the one submitted (i.e. if you decided to press submit on attempt 1, that's fine, if you wanted another 2 attempts, attempt 3 would be the one submitted).