A bag contains 5 white, 7 red and 3 black balls. If three balls are drawn one by one without replacement, find the probability that none is red.

Explanation

A= in first draw A white or black ball comes up


B= in second draw A white or black ball comes up


C= in third draw A white or black ball comes up



`P(A)=frac{8}{15} `

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P(B / A)=frac{7}{14}=frac{1}{2} `

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P(C / A cap B)=frac{6}{13} `

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therefore Required probability =P(A cap B cap C) `

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