Adam earned 2 points in the first round of competition. In the second round, he earned 7 points. In the final round, he earned 9 points. How many points did he earn in all?

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

Having a hard time understanding this question (see attachment).

X/y + 4y/x divided by x/y - 2y/x explain as in depth as you can how you simplfied the fractions. i don't know where to start on this : /