If \[^{n}{{C}_{r}}\] denotes the number of combinations of n things taken r at a time, then the expression \[^{n}{{C}_{r+1}}+{{\,}^{n}}{{C}_{r-1}}+\,2\times {{\,}^{n}}{{C}_{r}}\] equals [AIEEE 2003]

If \[^{n}{{C}_{r}}\] denotes the number of combinations of n things ta

1.	If \[^{n}{{C}_{r}}\] denotes the number of combinations of n things taken r at a time, then the expression \[^{n}{{C}_{r+1}}+{{\,}^{n}}{{C}_{r-1}}+\,2\times {{\,}^{n}}{{C}_{r}}\] equals [AIEEE 2003]
A.	\[^{n+2}{{C}_{r}}\]
B.	\[^{n+2}{{C}_{r+1}}\]
C.	\[^{n+1}{{C}_{r}}\]
D.	\[^{n+1}{{C}_{r+1}}\]
Answer» C. \[^{n+1}{{C}_{r}}\]

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If \[^{n}{{C}_{r}}\] denotes the number of combinations of n things taken r at a time, then the expression \[^{n}{{C}_{r+1}}+{{\,}^{n}}{{C}_{r-1}}+\,2\times {{\,}^{n}}{{C}_{r}}\] equals [AIEEE 2003]

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