What is the expected value?

Question

Suppose a person plays a gambling game where it is possible to lose $1.00, break even, win $3.00, or win $5.00 each time he plays.

In the long run, the player can expect to (win/lose)how many dollars $___?

Answer 1

-1, +3 or +5 each time

If with equal likelihood for each of the 3 possible outcomes then

the expected winnings are

1/3 times each, then sum all 3: -1/3 + 1 + 5/3 = 7/3 = 2 1/3 dollars = $2.33

or just add all 3 and divide by 3: -1+3+5 = 7, 7/3 = 2 1/3 dollars