Probability

Probability

What is Probability, Experiment, Outcome and Sample Space?



Probability is the measure of how many an event is

Experiment is a situation involving chance or probability

Outcome / Sample is the result of a single trial of an experiment

Sample Space / Event is all the possible outcome of an experiment (s) sample points

Example: "It is unlikely to rain tomorrow" :

Examples

The Formula?

Formula of Probability

Examples & Questions :-

Probability of a card (1st example)

A card is chosen at random from a deck of 48 playing cards.

There are 4 Queens and 4 Kings in a deck of playing cards.

What is the probability the card chosen is a Queen or a King?

The Answer is = 1/6

Solution

There are 4 Queens and 4 Kings, so the Number of ways it can happen = 8
There are 52 cards altogether, so the Total number of outcomes = 48


So the Probability the card of either Queens or King is

Examples 2

Alex has a bag with 9 blue sweets and 3 red sweets in it. She picks up a sweet at random from the bag, replaces it and then picks again at random. Draw a tree diagram to represent this situation and use it to calculate the probabilities that she picks:

(a) two red sweets

(b) no red sweets

(c) at least one blue sweet

(d) one sweet of each color


Solutions :

the probabilities that she picks:

 (a) two red sweets
 

(b) no red sweets

(c) at least one blue sweet

(d) one sweet of each color