Hello,
The key to doing these problems is writing the fraction for each event and multiplying them.
I will do the first problem for you.
First, you have to draw an ace. The chances of that are 4/52.
Then, you have to draw a jack. The chances of that are 4/51.
We changed 52 to 51, because we didn't replace the ace that we drew the first time.
Multiplying those fractions gives us the answer 4/663.
I hope this gets you started in the right directions,
MrEQ