To calculate a bet’s expected value, multiply the probability of each outcome by its value and then add up those results. For this bet, the expected value would be: ([⅙ probability of winning] × $200) + ([⅚ probability of losing] × –$10) = $33.33 $8.33 = $25 In other words, if you took this bet many times, the average amount you would win each time is about $25. Not bad money for simply rolling a die! This is a great bet to take, even though the most likely outcome is failure.
