Math puzzles!

...judging by those rules and what you posted:

8) 1. you can't win
9) 1. you can't win.

there's got to be something else you forgotten though, otherwise this is a "did you read the notes?" question

T.T besides 1. Geez I'm really out of it. I keep forgetting to mention stuff D:

9)163
1-20: 2 miss, 1 dart hits 1-20
21-40: 1 miss, 1 dart hits 1-20, 1 dart hits 1-20
41-60: 1 dart hits 1-20, 1 dart hits 1-20, 1 dart hits 1-20
61-80: 1 miss, 1 dart hits 1-20, 1 dart hits 3x 1-20
81-100: 1 dart hits 20, 1 dart hits 1-20, 1 dart hits 3x 20
101-120: 1 dart hits 3x 20, 1 dart hits 2x 20, 1 dart hits 1-20
121-140: 1 dart hits 3x 20, 1 dart hits 3x 20, 1 dart hits 1-20
141: 1 dart hits 3x 20, 1 dart hits 3x 20, 1 dart hits 3x 7
142: 1 dart hits 3x 20, 1 dart hits 3x 20, 1 dart hits 2x 11
143: 1 dart hits 50, 1 dart hits 3x 20, 1 dart hits 3x 11
144: 1 dart hits 3x 20, 1 dart hits 3x 20, 1 dart hits 3x 8
145: 1 dart hits 3x 15, 1 dart hits 50, 1 dart hits 50
146: 1 dart hits 3x20, 1 dart hits 3x20, 1 dart hits 2x 13
147: 1 1 dart hits 3x 20, 1 dart hits 3x 20, 1 dart hits 3x 9
148: 1 1 dart hits 3x 20, 1 dart hits 3x 20, 1 dart hits 2x 14
149: 1 dart hits 3x 13, 1 dart hits 50, 1 dart hits 3x 20
150: 3 darts hit 50
151: 1 dart hits 50, 1 dart hits 3x 17, 1 dart hits 50
152: 1 dart hits 3x 20, 1 dart hits 3x 20, 1 dart hits 2x 16
153: 1 dart hits 3x20, 1 dart hits 3x20, 1 dart hits 3x 11
154: 1 dart hits 3x 20, 1 dart hits 3x 20, 1 dart hits 2x 17
155: 1 dart hits 3x 20, 1 dart hits 50, 1 dart hits 3x 15
156: 1 dart hit 3x 20, 1 dart hits 3x 20, 1 dart hits 3x 12
157: 1 dart hits 50, 1 dart hits 3x 19, 1 dart hits 50
158: 1 dart hits 3x 20, 1 dart hits 50, 1 dart hits 3x 16
159: 1 dart hits 3x20, 1 dart 3x20, 1 dart hits 3x 13
160: 1 dart hits 50, 1 dart hits 50, 1 dart hits 3x 20
161: 1 dart hits 3x20, 1 dart hits 50, 1 dart hits 3x 17
162: 1 dart hits 3x20, 1 dart hits 3x20, 1 dart hits 3x 14
163: can't. You can do everything with combinations of 20 and 50s, but this one. 2 darts 3x 20s, 43 left can't be done, prime. 2x 50s, 63 left, can't be done coz there is no 21. 3x 20 + 50, 53 left can't be done, prime.

You also missed the bolded where you're required to end in a double.



Here: official rules

Double-out: Players must reach "0" exactly by scoring in a double point value segment.

With 32 points to go, a double 16 will end the game. A single 16 will still leave 16 to go, which can be gotten by throwing a double 8, and so on down the line. If an odd number is thrown, another odd number is needed to get back to a double possibility. If one less or one more than the exact score is hit, the player must assume the same score he had at the end of his last turn. (This is called busting.) The rest of the rules hold.

aka, if you get down to 1 point... you bust and have to go back to the previous score you had.