# Simple probability question but confused what distribution to use

A class has 70% females and 30% males. Students are selected at random, what is the probability that 7 students have to be selected before 2 males can be obtained?

Is this binomial distribution? Or not?

-
Either we know the size of the class, or we have to assume students can be picked twice. Which is it? Also, we need to know the precise meaning of "before 2 males can be obtained". –  Jack M Apr 24 '13 at 22:21
The question says to assume a really big class. Sorry if my wording was a bit too opaque. The actual word for word question is 'We select students at random, one at a time. What is the probability that we need to select 7 students in order to obtain 2 males?' –  tuba09 Apr 24 '13 at 22:24