As I mentioned, MGMAT Prep is a good investment but I do think to really ace both Verbal and Quant you need a bit more specifically on the quant side. The verbal of MGMAT is brilliant - it seriously helped me clarify my understanding and devise an attack strategy for my verbal. For Quant, the books are good to clarify concepts and lay down fundaments but I felt overall the quant tests from MGMAT are a bit more tedious than the actual GMAT which has slightly more witty questions which can make the real GMAT challenging. Along with this I would suggest to use the gmatclub Quant practise tests which are extremely representative. I suggest to focus on verbal for MGMAT and gmatclub tests for Quant.