In Country C, the unemployment rate among construction workers dropped from 16 percent on September 1, 1992, to 9 percent on September 1, 1996. If the number of construction workers was 20 percent greater on September 1, 1996, than on September 1, 1992, what was the approximate percent change in the number f unemployed construction workers over this period?
Since we're not given any concrete numbers here, only percents, we can plug in some numbers to help make this more workable.
Let's say there were 100 construction workers (including unemployed) in 1992. 16% of that 100 means there were 16 unemployed workers.
If the number of total workers increased by 20% in 1996, that means the total number of workers in 1996 was 120 (that's 120% of 100). If the unemployment rate was 9%, then there were .09*120 = 10.8 unemployed workers (this isn't really possible, but that's okay for now--we're only looking at percents, in the end).
So far, we have this:
Total 1992 workers: 100
Unemployed 1992 workers: 16
Total 1996 workers: 120
Unemployed 1996 workers: 10.8
Now we just need the percent change from 16 to 10.8. The difference is -5.2, so the percent change is -5.2/16 * 100
That's very close to -5/15, or - 1/3, so we can just estimate that this is about -33%. (D), -30% is closest.
2 Explanations