When you give the Venetian casino in Las Vegas $5 for a bet on the number 7 in roulette, you have a 37/38 probability of losing $5 and you have a 1/38 probability of making a net gain of $175.

I did $-5 x 37/38(.974) = -4.87

I did $5 x 1/38(.026) = + 0.13

= -4.74. The answer is -. 26 cents. What did I do wrong?