Dakshan
Hello everyone,
I'm starting my GMAT prep which is going to take place over the next 8-10 weeks, which I hope is enough for a 700+ score.
Quant is my strong suit as I was really good at math in school, but I've been out of touch for about 2.5 years now so I'm pretty rusty.
Can someone tell me the differences between OG2015 and 2016? I have the 2016 edition which says it has 25% new questions. Does this mean OG2015 has some content thats different from 2016 as well?
Also should I purchase the Verbal and Quant reviews too? I have heard they have just some additional content and have the same questions as the main book otherwise.
Thank you!

Hey Dakshan,
Yes, the OG has 25% new questions. This means that some of the content on OG 15 would be different.
The Verbal and the Quants review books are essential for your preparation and would give you the additional practice of Official questions.
No they do not have the same content.
Of the guides that you have listed, Official Guide Bundle 2016 is essential for your preparation. It is not a study guide and may not teach you much about how to strengthen your fundamentals, but it will give you questions that have appeared on the test and will give you valuable lessons from the solution of the questions.
You have a lot of time at your hands and many times this is counter productive. You would need close to 3 months to be well prepared for the test.
Regarding the other materials, there are primarily three methods in which you can go about with your preparation:
1. Classroom course
2. Studying from books
3. Online preparatory course.
Chose the one you are most comfortable with. Most of the courses including ours offer a trial period. Make use of that and see if the course fits your needs.
Once you are through with the concept building phase, I would recommend you to buy Exam Pack 1 and Question pack 1 from mba.com for additional official questions.
You should also follow a study plan as it will help you remain on track and organized.
You can find study plans here:
https://optimus-prep.com/free-gmat-section