Bernoulli's formula gives the probability of exactly k successes in n independent trials.
Bernoulli formula
$$P_{n,k}=C_{n,k}\cdot p^{k}\cdot q^{n-k}$$
where,
n— number of trials;
k— number of successes;
p— probability of success in one trial;
q— probability of failure (q=1−p);
Cn,k— number of combinations.