For example, 3/1 odds mean you profit three times the amount you wagered. AR$1 bet at 3/1 would pay outR$4 in total, or aR$3 profit and yourR$1 original wager. Conversely, 1/3 odds mean you profit a third of what you wagered. AR$30 bet on 1/3 odds would returnR$40 total, or aR$10 profit and yourR$10 original wager.
Odds of 7/5 mean you'll winR$7 for everyR$5 you wager on the A's. Conversely, the Rangers' odds of 5/8 mean you need to wagerR$8 to winR$5 on Texas. Another way to look at it: If the first number is larger than the second, you're betting on the underdog for a higher potential payout.