F to the second time F to the Third

How can you find the conditional probability of a given b as the fraction of b’s outcomes that also belong to a, and interpret the answer in terms of the model? i just need a good explanation

If a baby uses 15 diapers in 2 days, how many diapers will the baby use in a year?

8. kelly wants to buy a magazine that is $25. later the magazine was marked up an additional 20%. what is the new price?