You have a bag of chocolate candy . ten of them are red,7 are brown,12 are green, and 9 are blue . what is the probability that you pick a red candy , given that you have already picked a blue candy and have not replaced it?

I believe the answer to your question is 10/37.
The total of candies inside the bag was initially 38. Since a blue candy has already been picked and cannot be picked and cannot be replaced then the total number of candy remaining in the bag is 37. So the probability of choosing a red candy is now 10/37