149 : 1 is the odds against your winning the boat.
Step-by-step explanation:
It is given that,
The winner of a raffle will receive a 21-foot outboard boat.
The odds against any event is the ratio of the unfavorable outcomes to the favorable outcomes.
The number of possible outcome that you will win ⇒ 20
The number of possible outcomes that others wins ⇒ 3000-20 = 2980
To find the odds against your winning the boat :
Number of possible outcomes that one of the others wins : Number of possible outcome that you will win.
⇒ 2980 : 20
⇒ 149 : 1
Therefore, the odds against your winning the boat is 149 : 1
