Since a Bernoulli Distribution is defined only for a single experiment (one toss, in this case), this rather rules out the Bernoulli.
Would you advise me please on what is appropriate distribution calculation here
and how to set it up:
An unbiased coin is tossed repeatedly until a “tail” is observed for the second time.
Find the probability that it would require k tosses to achieve that
Disclamer:
This is a practice problem for entrance exam, and not a homework. If confirmation is needed send e-mail and I will send link to a problem on the web.