shruti290

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  • in reply to: probability #517

    shruti290
    Participant

    Thanks


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  • in reply to: permutation and combination #510

    shruti290
    Participant

    the correct answer is 36 and yours is 18


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  • in reply to: permutation and combination #509

    shruti290
    Participant

    i did not follow what u said and the correct ans is 505 i forgot to mention and i got it
    basically the question says tht atleast 2 didigts are identical which is just another way of saying tht at least one digit is repeated therefore the answe is
    5^4-5!
    that is the total no of ways- no digit repeated


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  • in reply to: probability #508

    shruti290
    Participant

    but where is the case where 2 colors will be missing?
    what i thought was tht first there are 90c10 ways in total now
    case1-draw 10 balls from the 30 red and 30 white balls tht means 60c10
    cse 2- 10 balls drawn frm 30 white and 30 blue balls tht means 60c10
    case3-10 balls frm 30 red and 30 blue tht emans 60c10
    now in all these 3 cases will also involve the cases where only red ,blue or white balss are drawn therefore to avoid double counting we subtract 3*30c10
    threfore my answer becomes
    3(60c10-30c10)/90c10


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Viewing 4 posts - 16 through 19 (of 19 total)