If the coefficients of the (n + 1) th term and the (n + 3) th term in the expansion of $(1+\text{x})^{20}$ are equal, then the value of n is:

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Aicharya · Accepted Answer

Solution: Coefficient of (r + 1) th term = Coefficient of (n + 3) th Then, we have ${^\text{20}}\text{C}_{\text{n}}={^\text{20}}\text{C}_{\text{n}+2}$ $\Rightarrow 2\text{n}+2=20$ $\Rightarrow \text{n}=9$

If the coefficients of the (n + 1) th term and the (n + 3) th term in the expansion of \((1+\text{x})^{20}\)…

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