 | 高校生レベルの英文の確率問題について質問があります。
問題文
There are damaged hard drive. 20% of them only the allocation sector are damaged. 70% of them only the nonessencial sector are damaged. 10% of cases both allocation sector and one or more nonessencial sector are damaged. A damaged drive is selected randomly.
問
1) If the drive is found ti have a damaged allocation sector, what is the probability that some nonessensial sector are dameged as well?
2)If the drive is found to have a damaged nonessencial sector, what is the probability that the allocation sector is damaged as well?
3)If the drive is found to have a damaged allocation sector, what is the probability that no nonessencial sectoris are damaged?
4)If the drive is found to have a damaged nonessencial sector, what is the probability that the allocation sector is not damaged?
自分の考えですが
1)、 2) は10％＝ 0.1 だと考えました。
3)は (0.2+0.1)*(1-0.1)＝ 0.27
4)は (0.7+0.1)*(1-0.1)＝ 0.72
恐縮ですがアドバイスよろしくお願いします。
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