It's beneficial for quickly preparing but i have a suggestion
It's beneficial for quickly preparing for the test. But, when I saw the video in which you quickly solved the problem on the screen, I needed to rewatch it again. Because we wouldn't know what do you do. You'd let us know time is really important with solving the different cases like GMAT. If you could change a little bit of orders, everyones knows what's the goal for this video.