Given:
A standard 6-sided dice is rolled.
If you roll an even number you get two points.
If you roll an odd number you lose one point.
To find:
The expected number of points per roll?
Solution:
If a dice is rolled, then the possible outcomes are 1, 2, 3, 4, 5, 6.
Odd values are 1, 3, 5 and the even values are 2, 4, 6.
The probability of getting an odd number is:
The probability of getting an even number is:
The expected number of points per roll is:
Therefore, the expected number of points per roll is 0.5.