
Answer:
Step-by-step explanation:
Given that one of the wagers in the game of roulette is to place a bet that the ball will land on a black number.
Probability will be 18/38 for black and red and 2/38 for green
We have
Colour   Black   Red   Green   Total
Number    18    18      2       38
Bet amt. Â Â Â 7 Â Â Â Â 7 Â Â Â Â Â 7
Win amt. Â Â Â 7 Â Â Â Â Â 0 Â Â Â Â 0 Â Â Â Â Â
Net win     0     -7    -7
Prob       18/38  18/38  2/38
Netwin*p    0     -126/38  -14/38
Expected value of win = -140/38 = -3.68