probability

This topic contains 3 replies, has 2 voices, and was last updated by  shruti290 5 years, 4 months ago.

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  • #497

    shruti290
    Participant

    if 7 balanced dice are rolled what is the probability that each of the six different nos will appear atleast once?


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  • #500

    rohit pandey
    Participant

    there are 7 different dices _ _ _ _ _ _ _
    for 1st dice it can take any 6 numbers but other 6 dices will have permutation of 6*5*4*3*2*1*6
    total no of events =6^7

    so probability=6*5*4*3*2*1*6/6^7

    maybe right maybe wrong


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  • #504

    rohit pandey
    Participant

    the answer is {6*7!/2!}/6^7

    realised the above answer is wrong
    first there are 7! ways for dice to get numbers since two numbers are same so divide by 2! and since there are six numbers that will be repeated there are 6 cases so multiply it by 6


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