Chance and Probability

Theoretical Probability:

The idea that things happen a certain number of times...

Coins:

There are 2 different sides...heads and tails...

The probability of guessing the right one is 1/2 = 0.5 or 50%

Cards:

How many cards in a deck? 52

How many colours? 2

How many suits? 4

How many individual cards per suit? 13

probability of...

picking a black card? 26/52 = 1 out of 2, or 1/2, or 50%

picking a heart? 13/52 = 1 out of 4, or 1/4 or 25%

picking a 7? 4/52 = 1 out of 13, or 1/16 or 6.25%

picking the ace of clubs? 1/52, or 1.9%

Dice:

6 sides

probability of rolling a 4: 1 out of 6, 1/6 or 16.7%

probability of rolling a 1: 1 out of 6, 1/6 or 16.7%

when we compound the probability with 2 dice, the numbers are different.

probability of rolling snake eyes: 1/6 x 1/6 = 1/36, or 2.8%

probability of rolling a combination adding to 8: what are the numbers rolled that add to 8?

2 and 6, 3 and 5, 4 and 4, but also 6 and 2, 5 and 3... there are 5 ways to get 8, 

so 5/36 or 5 out of 36 combinations, so 13.9% chance of rolling 2 dice and the sum is 8