A die has  sides, with each side displaying a number between . 

Let's first determine the probability of rolling a  or a  after John rolls the die a single time.

There is a total of  sides on a die and we have one value of  and one value of ; thus, our probability is:

This means that roughly  of John's rolls will be a  or a ; therefore, in order to calculate the probability we can multiply  by —the number of times John rolls the die.

If John rolls a die  times, then he will roll a  or a  roughly  times. 

A die has  sides, with each side displaying a number between . 

Let's first determine the probability of rolling a  after John rolls the die a single time.

There is a total of  sides on a die and only one value of  on one side; thus, our probability is:

This means that roughly  of John's rolls will be a ; therefore, in order to calculate the probability we can multiply  by —the number of times John rolls the die.

If John rolls a die  times, then he will roll a  roughly  times. 

A die has  sides, with each side displaying a number between . 

Let's first determine the probability of rolling a  after John rolls the die a single time.

There is a total of  sides on a die and only one value of  on one side; thus, our probability is:

This means that roughly  of John's rolls will be a ; therefore, in order to calculate the probability we can multiply  by —the number of times John rolls the die.

If John rolls a die  times, then he will roll a  roughly  times. 

There are four cards of each rank in a standard deck; since three ranks - jacks, queens, kings - are considered face cards, this makes twelve face cards out of the fifty-two. But two of those face cards - two red queens - have been removed, so now there are ten face cards out of fifty. This makes the probability of a randomly drawn card being a face card

.

Probability is determined by dividing the number of incidences of a specific outcome (in this case rolling greater than 4, or rolling a 5 or 6) by the total number of outcomes (there are 6 sides to the die).

Probability is determined by dividing the number of outcomes of a particular event by the total number of events. In a regular deck of playing cards, there are 52 cards and 13 diamonds.

A standard deck contains  cards including jacks, of which are red. Therefore, the probability is:

There are 13 yellow and red pebbles.  There are 25 pebbles total.  Therefor the probability of choosing a red or yellow pebble is .

First we need to determine the total number of marbles in the bag:

There are 9 green marbles, so the probability of drawing one of those 9 marbles out of 19 possible marbles is .

The probability (p) is equal to the number of a specific event (purple marbles) divided by the total number of events. The probability of NOT p (called q) is equal to In this example: