Suppose you flip a coin twice. what is the probability that you get tails on the first flip and tail on the second flip?

You can count all the possibilities (sample space) for tossing a coin twice. Possibilities are: HH HT TT TH. So there are four possible outcomes and only one satisfies your demand i. e. HT. Hence probability of getting HT = 1/4. Now let’s solve it in more conceptual way. Suppose you toss a single coin then P (H) = 1/2 and P (T) = 1/2 assuming that coins is not biased. When you toss a coin twice, the second event is independent of first event. Therefore P (HT) = P (H). P (T) = 1/4.

Hopefully.! You got your answer.

The possibilities are HH TT HT TH so to get TT you have a 1/4 chance (25%)