given eight students, three of which are females, if two students are
selected at random, without replacement, what is the probability that
both students are female?

Hello and thank you for your question.

The answers given in the comments are correct.

Here's an analysis that may make it clearer how this works:

On the first pick, there are 3 winning picks out of 8 possibilities,
so that's a 3/8 chance of being successful so far.

On the second pick, assuming the first pick ws successful, there are 2
winning picks out of 7 possibilities, so that's a further 2/7 chance.

Since you have to win both the first and second pick, the overall
probability is the product of 3/8 and 2/7 = 6/56 which simplifies to
3/28.

For a more complete explanatation, take a look at
http://faculty.vassar.edu/lowry/ch5pt2.html

Search terms used:
probability both students female

Good luck with your studies
Richard-ga

3/28      i wonder how i get an account that can answer questions in
stead of comment...

Total outcomes, selecting 2 at a time, male or female, is 28.
Probability of randomly selecting 2 females out of the 28 is 

            3!
 (3)     ---------
 (2)      2!(3-2)!      3
----- = ------------ = ---- = .1071
 28         28          28