The probability of picking one girl would be . That is because there are 5 girls out of the 12 students, and the probability of an event occuring is:
.
Using that same logic, the next student should be easier. We reduced the student population by 1, so we have 11 possible ways it can happen now instead of 12, so that gives us:, for the probability of picking a boy as the second pick.
And lastly, using the same logic shown above, the probability of picking a girl on the third pick would be:.
We are not done, though. We have the separate probabilities, but now we have to multiply then together to figure out the probability of this exact event happening:
Which when reduced is: