In Professor Plum's biology class there are 40 students. Of those students, 80 percent have puppies. Of those who have puppies, 25% also have parrots. How many students have both puppies and parrots?
Thoughts? Step-by-step reasoning:
We start with the initial numbers of students, 40 and multiply that by .8 for 40 * 0.8 = 32 who own puppies. That the number of students with puppies, 32, and multiply that by .25 to find out how many own both puppies and parrots, 32 * 0.25 = 8 who own puppies and parrots. The answer is 8.
Thus, the answer is 8.