0

enter image description here

I tried a few different ways and I end up getting it wrong. What is messing me up is years 1995 and 1996. I know there is a 30 percent increase somewhere but not sure where. Thanks

user60887
  • 2,935
  • I ran into that question today. If somebody phrases such problem at work, I would fire that person. Having studied advanced calculus and beyond where precision is important, I find these statistics GRE questions stupid, ill-posed in some cases, and harder to understand (not necessarily solve) than advanced topics in math. Don't let the GRE score be a measure of what you can do. Creativity > timed analytical skills, in any day, any time, anywhere. – Makketronix Apr 30 '18 at 05:29

2 Answers2

2

You're making this much too complicated. From 1990 to 1995, the percentage change in revenue was -15%, and from 1995 to 2000, it was +15%, so the answer is simply $$ \$800000 \cdot (1 - 0.15)(1 + 0.15) = \$ 782000.$$ This is a GRE question. They aren't going to ask you anything that can't be solved at a high school level of math.

heropup
  • 135,869
  • I thought that the 15% decrease or increase meant from year to year. – user60887 Jan 17 '14 at 02:25
  • 1
    I realize that's what you were thinking--but that is just too complicated for a typical GRE question. I do agree the wording is vague, however. If we did it the way you were thinking, it would look like this: $800000(1-0.15)^5 (1+0.15)^5 = 713960,$ but this is not one of the answer choices. – heropup Jan 17 '14 at 02:28
  • yeah that was what I was getting. I guess if its not an answer do it the other way. – user60887 Jan 17 '14 at 02:29
  • The subtlety of the intended interpretation lies in the phrase "The graph shows the percent changes in the annual city tax revenue...from 1990 to 1995 and from 1995 to 2000." What is meant by this is that from 1990 to 1995, the change in tax revenue for city B went down by 15% in that five-year period. But I agree that it is poorly worded. Sometimes I think that the GRE math section tests one's English skills more than the math itself...or even the Verbal section! – heropup Jan 17 '14 at 02:32
0

To decrease a number by $15\%$, multiply it by $0.85$. To increase it by $15\%$, multiply it by $1.15$.

So the answer is $$1.15 \times 0.85 \times 800000 = 782000.$$

user121926
  • 293