Question

Harlene tosses two number cubes. If a sum of 8 or 12 comes up, she gets 9 points. If not, she loses 2 points. What is the expected value of the number of points for one roll?

Answer 1

-(1/6)

Explanation:

Answer 2

P(8 or 12) = 1/6
P(not 8 or 12 = 5/6
Let the expected points fro one roll be X.

`E(X)=9*(1)/(6)-2*(5)/(6)=-(1)/(6)\ points`
The answer is -(1/6) points.