New Enroll in RBI Grade B New Batch - Starts on May 21

    Question

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

    Two hats are picked at random, what is the probability

    that one is blue and one is yellow?
    A 3/19 Correct Answer Incorrect Answer
    B 2/11 Correct Answer Incorrect Answer
    C 4/15 Correct Answer Incorrect Answer
    D 2/15 Correct Answer Incorrect Answer
    E None of these Correct Answer Incorrect Answer

    Solution

    Total number of hats = 6 + 4 + 2 + 4 = 16 Let S be the sample space. Then, n(S) = number of ways of drawing 2 hats out of 16 = ¹⁶C_2 = (16 × 15 )/( 2 × 1) = 120 Let E= event of drawing two hats so that one is blue and one is yellow. n(E) = ⁴C_1×⁴C_1= 4 × 4= 16  ∴ P (E) = (n(E))/(n(S))   = 16/120 = 2/15

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