I am having trouble completing all the questions (OG 13 + 2nd edition) in the daily study plan for the quant session and this is slowing me down considerably. Do you have any suggestions on how to complete questions faster so I stay on track? Should I ignore the 2nd edition questions (which seem generally easier) and focus only on OG13 questions where I dont have enough time?

The time it takes to complete each day's activities will vary from person to person. It also varies depending on which resource you use (GMAT Prep Now videos or MGMAT books). Also, some days take longer to complete.

I recommend that you complete all of problems for one day before moving on to the next day's activities. Sticking to one concept at time before moving on to the next concept will help promote mastery of each topic. It's also important to note that there are several math topics that build on previous math topics, so it's a good idea to build a strong foundation before moving on.

Don't worry if that will set you back time-wise. Day 42 is the last day that you learn new content, and the remaining days are devoted to taking practice tests and working on weaknesses. So, you can always catch up then.

Should I practice answering questions within a given time for example 20 questions in 40 minutes without reviewing answers after each question etc

Early in your prep, there's a danger in focusing too much on timing. In my view, this focus has the potential to actually hinder your preparation. I feel so strongly about the whole timing issue that I wrote two articles about it:
- Making Friends with Time on the GMAT - Part I (https://www.beatthegmat.com/mba/2011/06/ ... mat-part-i)
- Making Friends with Time on the GMAT - Part II (https://www.beatthegmat.com/mba/2011/07/ ... at-part-ii)
Executive Summary: Use a timer, but only to get an idea of what 2 minutes feels like. Later on (once you've covered all of the content), you can start working on your speed.

Executive Summary of the Executive Summary: Content First - Speed Second

So, take your time with the content. Also, be sure to review questions.

I hope that helps.

Cheers,
Brent