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If \ ^n Cr+\ ^n C(r-1)=\ \ ^(n+1)Cx ,\ t...

If `\ ^n C_r+\ ^n C_(r-1)=\ \ ^(n+1)C_x ,\ t h e n x =` `r` b. `r-1` c. `n` d. `r+1`

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Verified by Experts

`\ ^n C_r+\ ^n C_(r-1)=\ \ ^(n+1)C_x`
So,
`r+r-1=x`
`2r=2x`
`r=x`
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RD SHARMA-COMBINATIONS-Solved Examples And Exercises
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