How do I calculate expected value

Question

There is a spinner with 8 sides 3 have a picture of cards, 3 have a picture of dice, 1 has skull, and 1 has double.

The chance of picking the right card after the spinner lands on cards is 50%

The chance of guessing the right amount on a die is 11/36

Answer 1

Hi Bob,

The expected value for a probability question is simply the summation of P * X of all components, where P is the probability of X (the event) occurring.
i.e. E(X) = P₁X₁ + P₂X₂ + ... + P_nX_n

What are you trying to find the expected value of?