First, emphasize that data sufficiency tests concepts. The number is immaterial. It is trying to determine if the test takers know that rate multiplied by time equals distance. Data sufficiency questions take practice but with practice one can master them. Whether data sufficiency or word problem questions, test writers consistently use a number of decoys.
Questions always ask for several steps.
If a problem needs five steps, the answer to the fourth step might appear as one of the choices. There will be geometrical figures shown in the exam. Some will not be drawn to scale. Triangles might be inverted so the base is the top part of the figure. Test writers will use raw numbers and percentages.