>you should be able to solve this

There are 4 cards, consisting of 2 aces and 2 kings.

Scenario A
Your opponent draws a card first, not showing it to you. Then you draw a card and see it is an ace. What is the chance your opponent has an ace?

Scenario B
You draw a card first and see it is an ace. Your opponent then draws a card. What is the chance your opponent has an ace?