Answer:
The probability is
, in which p is the probability of a success on a single trial.
Step-by-step explanation:
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

In which
is the number of different combinations of x objects from a set of n elements, given by the following formula.

And p is the probability of X happening.
The trial is repeated 30 times:
This means that 
Find the probability of 5 successes given the probability p of success on a single trial
This is
. So



The probability is
, in which p is the probability of a success on a single trial.