Probability (deck of cards problem)

[Hill]

Two cards are drawn from a shuffled deck. What is the probability that both are red? If at least one is red, what is the probability that both are red? If one is a red ace, what is the probability that both are red?

Now I am able to do the 1st two parts of the question I am just stuck on how to find the probability of 2 red cards if one of them is a red ace.

I will attach my attempt at a solution in the pictures.

 

[Dr.Peterson]

Here are more readable images:




I agree with your answers to the first two, though I would have done the "at least one red" question as 1 - P(both black).

For the third, you've just found P(one red ace, other red). (But you are taking "one is a red ace" as "exactly one", while I took it as "at least one".) Put that into the definition of conditional probability.