Vlad's expected value of playing this game is -$1.50
From the information, we have that;
There are 6 x 6 = 36 possible outcomes when rolling two dice.
Each outcome has equal probability (1/36).
Determine value for each outcome:
If the sum is divisible by 3 (e.g., 3, 6, 9, 12), Vlad wins $6.
If the sum is not divisible by 3 (all other outcomes), Vlad loses $3.
Expected value = (Probability of winning x Win amount) + (Probability of losing x Loss amount)
Probability of winning = Number of winning outcomes / Total outcomes = (6/36) = 1/6
Probability of losing = (30/36) = 5/6
= (1/6 * $6) + (5/6 * -$3)
= $1 +( -15/6)
= 1 - 0.25
= $ -1.50