A random person having winked at you is given 10:1 odds of having a crush then shouldn't bob be the same?
No, 10:1 indicates that someone who have a crush on you has 10 times more probability to wink at you. Suppose random person has 1:30 chance of having crush on you. Then, if they wink, they have (1:30)*(10:1) = (1:3) odds of having crush on you. Compare that to Bob, who has 1:5 chance of having crush on you (not 1:30) before he winks, and (1:5)*(10:1) = (2:1) odds after he winks.
No, 10:1 indicates that someone who have a crush on you has 10 times more probability to wink at you. Suppose random person has 1:30 chance of having crush on you. Then, if they wink, they have (1:30)*(10:1) = (1:3) odds of having crush on you. Compare that to Bob, who has 1:5 chance of having crush on you (not 1:30) before he winks, and (1:5)*(10:1) = (2:1) odds after he winks.