The only way that bookstores can profitably sell books at below-market prices is to get the books at a discount from ...

BenMingov May 9, 2020

Hi Tejas, thanks for the question.

I think anywhere from 1.5-2 minutes on a question like this is good. Even a little over 2 minutes is totally reasonable if you are banking time from some shorter and easier questions.

The key to questions like these is to be lightning fast with your translation from sufficient/necessary languages to your conditional diagram. You'll notice that it creates one long chain and it contrapositive.

The other confusing point to this question is that it is asking Cannot Be True, which is much less common than Must Be True. So I wouldn't worry if this question threw you off timing wise, unless the conditional language was giving you pause. If that is the case, then I would recommend spending more time going from sufficient/necessary language to diagrams and making inferences from those diagrams.

I hope this helps. Please let me know if you have any other questions or would like me to elaborate further.