ExamBro
ExamBro
JEE Advanced · Mathematics · 6. Binomial Theorem

Let \(X=\left({ }^{10} C_1\right)^2+2\left({ }^{10} C_2\right)^2+3\left({ }^{10} C_3\right)^2+\ldots+\) \(10\left({ }^{10} C_{10}\right)^2\), where \({ }^{10} C_r, r \in\{1,2, \ldots, 10\}\) denote binomial coefficients. Then, the value of \(\frac{1}{1430} X\) is _____________.

  1. A 646
  2. B 514
  3. C 562
  4. D 612
Verified Solution

Answer & Solution

Correct Answer

(A) 646

Step-by-step Solution

Detailed explanation

X=r=0nr.nCr2;n=10
X=n.r=0nnCr. n-1Cr-1
X=n.r=1nnCn-r. n-1Cr-1
X=n. 2n-1Cn-1;n=10
X=10. 19C9
X1430=1143.19C9
=646
From JEE Advanced
Explore more questions on app