Think about probability as (size of group satisfying the condition) divided by ( total size of group).

So for the first problem it is:

(total number of non-light smokers) / (total number of people).

The second problem is conditional probability: Imagine I select a person at random and don't show you who they are. All I tell you is that the person selected is a nonsmoker. Now tell me how likely it is that they are a woman?

For the last problem assume that the sample group represents the actual population's proportions of smokers to non-smokers, heavy to light, etc. So what percentage of the total sample are male heavy smokers? What number of people is this percentage of 13,000?