Multiple choice

A basket contains 6 White 4 Black 2 Pink and 3 Green balls. If four balls are picked at random, what is the probability that at least one is Black? एक टोकरी में 6 सफ़ेद 4 काली 2 पिंक और 3 हरी गेंद हैं। यदि चार गेंदों को यादृच्छिक रूप से चुना जाता है, तो क्या संभावना है कि कम से कम एक काली हो?

  1. 69/91

  2. 56/91

  3. 23/91

  4. 17/91

  5. 19/91
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A Correct answer
Explanation

Total balls = 6+4+2+3 = 15. Ways to choose 4 from 15 = 15C4 = 1365. Ways with no black balls = choose from 11 non-black = 11C4 = 330. Probability of at least one black = 1 - (330/1365) = 1035/1365 = 69/91. This uses complementary probability.

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