gaspersic/freeCodeCamp
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Probability index.md file updated (#27836)

Browse Source 
index.md file updated with more info, some examples and cases.
This commit is contained in:
Anas Salam
2019-06-25 03:24:03 +05:00
committed by Randell Dawson
parent a4c214d877
commit ae33d5888f
1 changed files with 44 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

45
guide/english/mathematics/probability/index.md
View File

@@ -5,7 +5,50 @@ title: Probability
The probability of an event is the chance that an event is going to occur. The probability of an event is the chance that an event is going to occur.
Probabilities generally range from 0 to 1, with 0 indicating that an event will never happen and 1 that an event will happen for certain. Probabilities generally range from 0 to 1, with 0 indicating that an event will never happen and 1 that an event will happen for certain. <br>
The total of all probabilities will always sum up to 1.<br>
If the probability of a event happening is 0.75, then the probability of an event NOT happening will be 1 - 0.75 = 0.25, (the event not happening is calculated as reverse of this event happening).
<b>Example 1:</b> <br>
A coin has 2 sides, (Head and Tail).<br>
When an unbaised coin is flipped, there are 2 possibilities. The chances of Head appearing is 1/2 and similarly a Tail appearing is 1/2.<br>
The total of all outcomes will always be equal to 1, like in this case 1/2 + 1/2 = 1.
<b>Example 2:</b> <br>
A dice has 6 sides, (1, 2, 3, 4, 5 and 6).<br>
When an unbaised dice is rolled, each side has a probability of 1/6 or (0.1667) appearing.<br>
Similarly in this example too, the total of all outcomes will be 1, (0.1667 + 0.1667 + 0.1667 + 0.1667 + 0.1667 + 0.1667 = 1).
<pre>
<b>Case 1:</b>
chances of an odd number appearing is 3/6, (1, 3 and 5).
<b>Case 2:</b>
chances of number 6 NOT appearing is 5/6, (1 - 1/6).
</pre>
<b>Example 3:</b> <br>
A standard deck of cards has 52 cards, consisting of 4 suits - 2 Red suits (Hearts &#9829; and Diamonds &#9830;) and 2 Black suits (Spades &#9824; and Clubs &#9827;). And each suit has 13 cards with an Ace, 2, 3, 4, 5, 6, 7, 8, 9, 10, Jack, Queen and King. <br>
The probability of each card being withdrawn is 1/52. <br>
<pre>
<b>Case 1:</b>
chances of a Red card being randomly drawn from a standard deck of cards is 26/52, (13 Diamonds + 13 Hearts = 26 total Red).
<b>Case 2:</b>
chances of number 5 appearing is 4/52, (one from each Suit).
<b>Case 3:</b>
chances of Ace of Spades appearing is 1/52, (only 1 Ace in Spades Suit).
<b>Case 4:</b>
chances of a Face card appearing is 12/52, (3 Face cards in each Suit namely Jack, Queen and King)
<b>Case 5:</b>
chances of 8 of Hearts NOT appearing is 0.98, (1 - 1/52).
</pre>
<!-- The article goes here, in GitHub-flavored Markdown. Feel free to add YouTube videos, images, and CodePen/JSBin embeds --> <!-- The article goes here, in GitHub-flavored Markdown. Feel free to add YouTube videos, images, and CodePen/JSBin embeds -->