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수학동아 - 폴리매스
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함께 풀고 싶은 문제
창의력을 기를 수 있는 수학 문제 또는 퍼즐을 내는 곳입니다.
[창의 퍼즐] [확률] 닉넴 바꿨습니다(함정있음)
infinitepi 2020.07.23 23:57 조회 575
문제 푼 사람 0명
공유하기
페이스북 트위터 카카오톡 카카오스토리 네이버블로그 네이버밴드

폴리매스에는 5000명의 회원이 있다.

그런데, 그중 열심회원 100명과 안 열심회원 4900명이 있다.

어느 날 열심회원이 닉넴을 바꿀 확률은 1%, 안 열심회원이 닉넴을 바꿀 확률은 0.1%일 때,

다음을 구하여라.

 

(1) 오늘 아무도 닉넴을 바꾸지 않을 확률

(2) 어느 날 아무도 닉넴을 바꾸지 않을 확률

이 문제 어떠셨나요?

글쎄요

0

어려워요

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댓글 4
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  •  
    △π Lv.9 2020.07.24 07:49

    ? 파이가 하나 더생겼네?

    신입파이님 안녕하세요

    댓글 작성하기 좋아요0 댓글수3
    •  
      아엘 Lv.7 2020.07.28 05:22

      아ㅋㅋㅋ

      이제 파이는 3명이죠?

      좋아요0
    •  
      우럭 Lv.9 2020.08.03 18:14

      한명 추가요

      좋아요0
    •  
      파이파이 Lv.9 2020.08.03 18:15

      5명

       

      초코 삼각 파이 무한 한국

      오... 많다.

      좋아요0
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