Probability of selecting one card from a standard deck

Note the use of “and” and “or” in the problems.

“And” indicates the card contains both characteristics. For example, if asked to find the probability of picking a seven and a black card, then you are looking for cards that are both seven and black. This would be the seven of spades and the seven of clubs

"Or” indicates the card contains either or both of the characteristics. For example, if asked to find the probability of picking a seven or a black card, then you are looking for all cards that are either a seven, a black card, or both (but do not count any cards twice). There are 26 black cards and 4 sevens. This is not 30 total cards, because the two black sevens were counted in each group, so counting the cards in the above diagram, you can see that there are 28 cards that are seven, black, or both.