A quiz app serves a learner three questions, one after another. For each question the app picks a topic uniformly at random and independently from a fixed list of 5 topics — nothing stops the same topic from being picked more than once.
Recording the ordered triple of topics gives a sample space of equally likely outcomes.
What is the probability that at least two of the three questions come from the same topic?
Give your answer as a decimal rounded to 2 decimal places (for example, 0.37).