I need help with B ASAP because work is due tomorrow and Im seriously stuck. I have tried so many, please help.

Part A is correct; good job.
The universe is even numbers between 1 and 25, that's 2 thru 24. Count; there are twelve of them.
There's only one of them in the intersection of A and B, namely 8.
So the probability is one in twelve.
Answer: 1/12