In my learning journey, I have experienced that the last 15 days should be for GMAT mocks or GMAT tests. I have given the GMAT exam three times. The first time my score was 650 (Q 47, V 32) and I had prepared for two months. The second time I wrote my GMAT exam after three months and I improved by 30 points. My score was 680 (Q 48 and V 34). Third time I purchased a course named target verbal 44 plus from VerbalHub. The course trained me for the GMAT shortcut and taught me how to use GMAT study material in which the last 15 days were crucial. The course was for two months but I learned a lot from this course. I am summarizing the whole course keeping in mind GMAT prep in 40 days. By the way, my final score is 750 (V43, Q51).