Of police academy applicants, only 25% will pass all the examinations. suppose that 12 successful candidates are needed. what is the probability that, by examining 20 candidates, the academy finds all of the 12 persons needed?
I used a binomial probability on this one, since there are two outcomes (either pass or fail); the events are independent (the probability of one person passing does not influence the probability of another passing); and there are a fixed number of trials (in this case, 20).
For binomial probabilities, we use the formula: [tex]_nC_k=p^k*(1-p)^{n-k}[/tex]
