Originally Posted by

**nvwxgn** I need help with the following percentage question:

In a 400-people population, it has been done examinations to diagnose anemia and intestinal parasitism. The results made it clear that:

- 80% of the people with anemia have also intestinal parasitism;

- 50% of the people with intestinal parasitism have also anemia;

- 220 people have neither anemia nor intestinal parasitism.

Out of the 400 people, what is the percentage of people with anemia?

I know that the answer is 25%, but how do I get at it?