We need to figure out what the problem is really asking. I just stated my interpretation; do you think I am right?
As I read it, the answer is merely: "
The answer you got, which is greater than 1, can't be correct, because probabilities can't be greater than 1." I think that's all they want.
Or, as I hinted earlier, you could explain specifically why the method, not just the answer, is wrong: You can't just add two probabilities, because the formula for "or" is
P(A or B) = P(A) + P(B) - P(A and B)
The two events overlap, so you have to subtract that overlap, which will bring the answer down below 1. That is, in adding, you will have counted even numbers greater than 30 twice.
On the other hand, if you think it is asking for the probability, you can either do what pka showed (which I imagine may be written in a style a bit over your head), or just make a table showing all 144 possible products, mark those which are either even or greater than 30, and count them. You should get the number pka gave (assuming he didn't miss anything). Then put that over 144, and you have the answer.
I dislike questions that are as hard to interpret as this one is; they lead to unnecessary frustration, often over very simple problems.