One important thing to note when dealing with probability problems is to look for the words 'or' or 'and'. If you encountered 'or', you'll have to add the probabilities. If you encounter 'and', you'll have to multiply them.
In this problem, you'll have to add the probability for the males and the probability for the smokers. Thus,
An integer is any number positive or negative. A whole number would not have a decimal and if it were a rational number it could be written as a ratio.
