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 just 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.

I hope that helps.

Cheers,
Brent