Read easier passage in 2-3 minutes & understand the basic gist of it. If the
passage is really tough you can take up to 4 minutes, but not more than 4 mins in any case. Then each question should not take more than 45 seconds.

Important Tip: We also advice against jumping to questions first & then looking
for answers in the paragraph. Reading essay first makes answering "main point"
& "summary of essay" questions seem like a cakewalk.

With these speeds you should achieve accuracy > 85 % in all practice sets and you will do well in RC in GMAT

Since GMAT RC passages vary in length and have different numbers of questions, it might be best to do a set of, say, 25 questions at a time if you're worried about timing. If you're doing the easier questions early in the official guide, you should ideally be able to comfortably complete 25 questions in under 50 minutes; if you're attacking a much tougher set (either the last few questions in the OG, or a nasty LSAT RC section), then it might be OK to take a little bit more than two minutes per question on average. Many of my best students need about 55-60 minutes for a set of 25 LSAT RC questions, and they end up doing just fine on the actual GMAT in terms of timing.

Either way, I'm not sure that you'll be very happy timing each individual passage, since they are so different from each other. And longer sets help build your GMAT test-taking stamina, anyway.

I hope this helps. Good luck with your studies, saulzur!