Question 1147351
1/38 * +280 = +140/19
37/38 * -8 = -148/19
<pr>
Add these two values together to get -8/19.  This is the expected value of the game.  (About -$0.42.)
<pr>
If you play the game 1000 times, the you could expect to lose: 1000*(-8/19) dollars...or, -8000/19 dollars.  That's about $421.05.