https://www.keithschwarz.com/darts-dice-coins/

https://oldschool.runescape.wiki/w/Drop_rate

์œ— ์‚ฌ์ดํŠธ ์ฐธ์กฐ


N์ฒœ๋ฒˆ์˜ n๋ฒˆ์˜ ํ™•๋ฅ ย 

1 - (1 - 1 / N)โฟ

์˜ˆ์‹œ) 1์ฒœ๋ฒˆ์˜ 1๋ฒˆ์˜ ํ™•๋ฅ ์€

1- ( 1-1/1000) =ย 1 - 0.999ย  = 0.001%


๋ฒ”์œ„๋Š” 0.00 ์—์„œ 1.00 ๊นŒ์ง€


๋งŒ์•ฝ ๋ฌด๊ฒŒ๊ฐ์ด ์—†๊ณ ย ๋“œ๋กญํ•  ์•„์ดํ…œ ๊ฐฏ์ˆ˜๊ฐ€ 10๊ฐœ๋ผ๋ฉดย ๊ฐ ์•„์ดํ…œ ๊ฐ’์„ 1/10ย ํ•˜๋ฉด ๋œ๋‹ค.

๊ทธ๋Ÿฌ๋ฉด 0.1+ 0.1+ 0.1...ย = 1

1/n


์•„์ดํ…œ๋“ค์—๊ฒŒ ๋ฌด๊ฒŒ(weight)๊ฐ์„ ์ฃผ์ž, ์˜ˆ๋ฅผ ๋“ค์–ด

๋ชฉ๊ฒ€์—๋Š” 50%, ์ฒ ๊ฒ€์—๋Š” 25%, ๊ธˆ๊ฒ€ 10% , ๋‹ค์ด์•„๊ฒ€ 1%ย ์ •๋„์˜ ํ™•๋ฅ ์„ ์ฃผ๊ณ ์‹ถ๋‹ค, ๊ทธ๋Ÿฌ๋ฉด


1/2, 1/4, 1/10๋ฅผ ๋ถ„๋ชจ ํ†ตํ•ฉํ•ด 50/100, 25/100, 10/100

ํ•ฉํ•ด์„œ 0.85, ๋‚จ์€ 0.15๋ฅผ ์˜ˆ์™ธ์ ์œผ๋กœ ๊ฝ์œผ๋กœ ๋‘๊ฑฐ๋‚˜ย 

๊ฐ ์•„์ดํ…œ๋งˆ๋‹ค ๋‚˜๋ˆ  100%๋กœ ๋งŒ๋“ค๋ ค๋ฉด

50 * 100 /ย 85 = 58.8

25 * 100 / 85 = 29.4

10 * 100 / 85 = 11.7

ํ•ฉํ•ด์„œ 99.9ย 



์—ฌ๊ธฐ๊นŒ์ง€ํ•˜๊ณ  ์ฝ”๋“œ์— ์ ์šฉํ•ด๋ด„