Odds of 7/5 mean you'll win $7 for every $5 you wager on the A's. Conversely, the Rangers' odds of 5/8 mean you need to wager $8 to win $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.
In many cultures, the number 7 is associated with luck, fortune, and positivity. This association has been carried over into the world of slot machines, where the appearance of the number 7 on the reels is often linked to winning combinations and bonus features.