Well, what do you know about probability? For example, if A and B are independent events, what is the probability of "A and B"? That's a pretty fundamental property- in fact, it is part of the definition of "independent" so if you know that word, you should know the formula. The second problem is even easier- again it is a fundamental property of "independent".
So, if you don't know what "independent" events are- you should look it up!