LOL. Okay, I was thinking perhaps of the difference between a surgeon's scalpel versus a sledge-hammer approach.
I suppose focusing on the more difficult questions would be one efficiency. In DS' case though, he actually missed a couple of really easy questions (level 2) as well as a couple of harder ones (level 4/5). Of course, it also may be that he is taking too long to answer some of the high difficulty questions such that practicing those question could ensure that he has enough time to complete the test.
