Brainteaser iconBrainteaser - Opening Envelopes

Opening Envelopes
You have two envelopes in front of you. Each envelope has an equal chance of containing either a blue or red card inside. You already know one of these envelopes holds a red card.

What is the probability that the other envelope also contains a red card?

How does this change if you are told the first envelope you picked contains a red card?