Always spend a minute to read the chart/graph and understand generally what's going on. It's worth the investment in time.
For the first question:
Note that it asks "which of the following MUST be true?" Simply try to imagine a scenario in which it isn't true and if you can, then it isn't correct.
A. Less than 55 percent were male managers.
We can answer this one without a calculator. 550 would be 55% of 1000, right? But the survey has 1200 people in it, so there must indeed be less than 55% male managers.
B. Of the male managers, more identified work experience as an important characteristic to consider than identified proficiency in English.
Trap! We see that more managers require work experience than English. If you assume now difference between the male and female managers' preferences, than this is true. But we shouldn't assume anything. What if male managers are less likely to identify work experience as important than female managers? Then this statement may not be true. So B is out.
C. Less than 60 percent of the male managers identified specific occupational skill as important to consider.
Basically the same trap as B. This one is also out.
For the second question:
If you look up the appropriate info you get 72% and 55%, respectively. Use the "change over original" formula. In this case the change is the difference between 72 and 55, or 17. The original would be 55. Thus, 17/55. Again, we don't need the slow, clunky calculator. These numbers look sloppy but if you multiply 17 by 3 you would get 51. Thus, 17/51 = 1/3 so 17/55 should be a little less than that. D fits.
For the third question:
This is an overlapping set. You can ID it because they can value following directions AND/OR computer expertise, or neither. The easiest way to do an overlapping set problem is NOT a Venn diagram, but an overlapping set matrix. It's not easy to depict in a comment box, though. Anyway, draw three vertical lines and three horizontal lines to make a table. In this problem, I'd label the columns "Follows Directions," or FD, and "Not Follows Directions," or NFD, and Total. The rows, similarly, will be labeled "Computer Expertise," or CE, "Not Computer Expertise," or NCE, and Total again. I've made a poor attempt at a matrix below. The upper left box represents the 48 percent who answered that they valued both qualities. We can look up from the table how many value CE and FD and fill those out as below. The total, 100, (since we're dealing in percents,) goes in the lower right.
FDNFDTotal
CE48 58
NCE
Total65100
Looks good. Now we can reason that every two columns should add up to the total column, and every two rows should add up to the third row. For example, if 58% value CE then 42% must NOT value it, since the two possibilities must add up to 100. If we fill out the rest of the table we should get something like this:
FDNFDTotal
CE48 10 58
NCE17 25 42
Total65 35100
So 25% valued neither quality. It's D.
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