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    Question

    A box contains 6 red, 4 blue, 2 green and 4 yellow pencils.

    If two pencils are picked at random, what is the

    probability that either both are green or both are yellow?
    A 6/155 Correct Answer Incorrect Answer
    B 5/123 Correct Answer Incorrect Answer
    C 7/120 Correct Answer Incorrect Answer
    D 9/145 Correct Answer Incorrect Answer
    E none of these Correct Answer Incorrect Answer

    Solution

    Total number of pencils = 6 + 4 + 2 + 4 = 16 Let S be the sample space. Then, n(S) = number of ways of drawing 2 pencils out of 16 = 16C2 = `(16xx15)/(2xx1)` = 120 Let E= event of drawing 2 pencils so that that either both are green or both are yellow = n(E) = 2C2 + 4C2= 1+6 =7 [if gte msEquation 12]>∴ [if !msEquation]--> [endif]-->P (E) =`(n(E))/(n(S)) = 7/120`

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