Hi Roland2rule,
We're told that in a survey of 200 people, 20% of the men and 10% of the women are athletes and that 29 people are athletes in total. We're asked for the number of women in the survey. This question can be solved by TESTing THE ANSWERS. Even if the number 100 were not in the Answer Choices, it would probably help you to see the 'pattern' behind these numbers if you TESTed a group of 100 men and 100 women....
20% of 100 men = 20 male athletes
10% of 100 women = 10 female athletes
20+10 = 30 total athletes
This is just a little TOO HIGH (there are supposed to be 29 athletes), so we have to increase the number of women and decrease the number of men a bit. Based on the remaining answer choices, there's only one answer that makes sense.
Final Answer: D
GMAT assassins aren't born, they're made,
Rich