If he wins, his net winning is only 75 cents because he paid
$1.25 to play, since $2.00-$1.25 = $0.75. If he loses he
loses the $1.25 he paid to play, indicated by a negative
number.
Roll X P(X) E(X) = X∙P(X)
--------------------------------------------
2 $0.75 1/6 ($0.75)(1/6) = $0.125
1,3,4,5,6 -$1.25 5/6 (-$1.25)(5/6) = -$1.041666667
-----------------------------
Total expectation = -$0.916666667
So in the long run, he'll average losing about 92 cents a game.
Edwin