From my experience is there are alot of problems which will be similar or look up and then there will be a bunch where I say "Turn the page". Even if you can figure out what they are talking about, the amount of time required will be too much. Just Turn the page. The calculation are 33% which is 17 problems, for each type of problem you my expect one or two that are pretty easy if you know the material and there will one on that material where you just turn the page. You need about %50 to pass so focus on the parts that more reasonable and get them right. Time is the big issue on the survey and seismic exams, dont waste any time on difficult problems, you can alway go back and work them last.