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

    Question

    In a biased coin the probability of getting a head is

    0.6, if we toss a coin 10times, what is the probability of getting exactly three heads?
    A 1 Correct Answer Incorrect Answer
    B 3 Correct Answer Incorrect Answer
    C 4 Correct Answer Incorrect Answer
    D 2 Correct Answer Incorrect Answer

    Solution

    Probability of getting a head =0.6 =6/10=3/5 Probability of getting not head=1-3/5 =2/5 Direct shortcut- n Cr(P)r(1-P) n-r Then now Probability= =10C3 (3/5)3(2/5)7 = [(10×9×8)/3×2] × (33×27)/510 = (34×210)/59

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