If npr=nCr. X then x=?

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Answer 1 · 2018-04-20T14:55:42

#X=r!#

We know that,

#color(red)((1)nPr=(n!)/((n-r)!)#

#color(red)((2)nCr=(n!)/((n-r)!r!)=(nPr)/(r!)#

We have,

#nPr=nCr*X#

#=>X=(nPr)/(nCr)#

#=>X=(nPr)/((nPr)/(r!))#

#=>X=(nPr)/(nPr)*(r!)#

#=>X=r!#