Sorry it took me so long to respond. I am not sure what is the difference between solving linearly and doing mock test. I always timed myself on the Gmat prep. After I do the Math section I would sometimes skip the verbal and go to the end of the test. Then you can review all questions on your Math section, so I would go through the math and use print screen to save all questions I did wrong or found difficult. Then I will try to solve them and I will search them on this forum to see if there is a better way to approach them. Usually there was. Keep doing this multiple times until you feel very comfortable with approaching every type of problem. Hope this helps.