practice practice practice under timed conditions.... thats the best way to learn the concepts well enough to answer quickly...
It is much better to guess incorrectly then to leave questions unanswered... there is a penalty for unanswered questions, beyond just getting them wrong of course...
and you can click on the timer to hide it if its that distracting...
but in any case, you just need to practice under timed conditions until you are a mathamatical speedy gonzalez