Every Bet, the Same Edge

A casino wheel has 50 equally likely pockets: the numbers 1 through 48, plus two green house pockets. Three bets are offered, each staking \$1: (a) "low", covering numbers 1 through 24, pays 1 to 1; (b) a single number, pays 47 to 1; (c) a column of 16 numbers, pays 2 to 1. Compute the expected profit per dollar for each bet. What do you notice, and what is the general principle?