If ²⁰Cᵣ is the coefficient of xʳ in (1 + x)²⁰... | Binomial Theorem

JEE Main 2021

26-08-2021 S1

Question

If ${ }^{20} \mathrm{C}_{\mathrm{r}}$ is the co-efficient of $\mathrm{x}^{\mathrm{r}}$ in the expansion of $(1+\mathrm{x})^{20}$, then the value of $\sum_{\mathrm{r}=0}^{20} \mathrm{r}^2{ }^{20} \mathrm{C}_{\mathrm{r}}$ is equal to :

Select the correct option:

$420 \times 2^{19}$

$380 \times 2^{19}$

$380 \times 2^{18}$

$420 \times 2^{18}$

✓ Correct! Well done.

✗ Incorrect. Try again or view the solution.

Solution

Question Tags

JEE Main

Mathematics

Medium

Start Preparing for JEE with Competishun

Report Issue