To find the probability of an outcome, find the total number of ways that event can happen divided by the total number of possible outcomes.

There are 52 cards in a deck of cards, so there are 52 total possible outcomes. Of those, there are 26 black cards, and 4 twos.

However, of those 4 twos, two have already been included when we counted the 26 black cards (the 2 of clubs and 2 of spades), thus there are only two additional twos to add to our total of 26 black cards.

This yields 28 possibilities, which when divided by 52 reduces to:

To find the probability of an event, determine the number of ways the event can happen, and divide that by the total number of possible outcomes.

Because there are 52 cards in a deck of cards, the total possible number of outcomes is 52.

Since there are 3 face cards (Jack, Queen, King) and four suits, there are a total of 12 face cards.

To find the probability of an outcome figure out the number of ways the specified event can occur (rolling a number greater than ), divided by the total number of outcomes. Since there are  possible numbers to roll, the total number of outcomes is . The numbers greater than  are:  for a total of  possibilities. Thus the answer is:

.
(Note,  is not included in "greater than", if it said "greater than or equal to " it would be).

To find the probability of an event, find out how many ways that specific event can happen and divide it by the total number of possible outcomes. The only numbers less than or equal to  on a  sided die are  and . There are  possible outcomes. Thus the reduced fraction is: 

Even though I and II may seem like rarer outcomes, all of the answer choices have an equal probability of occurring, as the probability for each outcome is 0.50 in each flip and the probability for each of these sequences of coin flips equals (0.50)^7.

 are the prime numbers on a die, so since there are 6 sides the odds would be .

To calculate the odds of a chain of events, multiply the events' probabilities together. Since we want the lightning to strike any rod target on the first bolt, our odds of success are . The next bolt cannot hit the non-rod target nor the target that was already struck, so our chances are now . The last bolt cannot strike either of the previous two targets or the ground, so our odds drop further to . Multiply these individual probabilities to get the probability of this chain of events:

To find the odds of a particular chain of outcomes, find the product of the odds of each required step's outcomes.

In this case, we can assume that Connell got the first three questions right (in other words, the order doesn't matter since it doesn't noticeably bias the later results).

So the odds of this are:

The odds of getting a problem wrong with a blind guess, on the other hand, is , so the next seven questions being wrong have an odds of:

Lastly, multiply our two individual probabilities together:

Thus, the odds of getting this exact result are 

This is a probability problem.  What you must first decide is what is the probability of getting the outcome you want?  

The probability of getting tails on each of the three coins is  or . 

Since we have three coins, we multiply their individual probabilities to get the final answer:  

 .

To find probability, you must take the # of desired outcomes divided by the total. Thus,