Explain! Prize! Thank you

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

Find the x-intercepts of the parabola withvertex (1,1) and y-intercept (0,-3).write your answer in this form: (x1,if necessary, round to the nearest hundredth.

Which of the following parabolas opens up?