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Math Help - 1-1

  1. #1
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    1-1

    Determine the # of 1-1 correspondences in 2 sets each containing 5 elements, 6 elements, n elements.
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  2. #2
    Like a stone-audioslave ADARSH's Avatar
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    Wink Its here

    Hello fifthrapiers!
    If
    A={x1,x2,x3.....xM}
    B={y1,y2,y3.....yN}
    For 1-1 functions from A to B
    Here
    x1 can take N images
    x2 can take N-1 images
    x3 can take N-2 images
    .............
    ...........
    xM can take N-M+1 images
    Thus no. of mappings =N(N-1)(N-2).... (N-M+1)

    = (N)!/(N-M)! , if N>=M
    else= 0 , if N<M
    Your Question Has N=M.
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