JEE Math Practice Question
$$\sum\limits_{\begin{matrix} {i,j = 0} \\ {i \ne j} \\ \end{matrix} }^n {{}^n{C_i}\,{}^n{C_j}} $$ is equal to
- A.$$2^{2 n}-{ }^{2 n} C_{n}$$
- B.$${2^{2n - 1}} - {}^{2n - 1}{C_{n - 1}}$$
- C.$$2^{2 n}-\frac{1}{2}{ }^{2 n} C_{n}$$
- D.$${2^{2n - 1}} + {}^{2n - 1}{C_n}$$
Want to know if you got it right?
Answer this and thousands more real JEE previous-year questions free, get graded instantly, and climb the global ranked leaderboard.
Practice JEE free →More JEE Math questions
- What is the total number of distinct x \in \mathbb{R} for which \left|\begin{array}{ccc}x …
- Let m be the smallest positive integer such that the coefficient of x^{2} in the expansion…
- What is the total number of distinct x \in[0,1] for which \int_{0}^{x} \frac{t^{2}}{1+t^{4…
- Let \alpha, \beta \in \mathbb{R} be such that \lim _{x \rightarrow 0} \frac{x^{2} \sin (\b…
- Let z=\frac{-1+\sqrt{3} i}{2}, where i=\sqrt{-1}, and r, s \in\{1,2,3\}. Let P=\left[\begi…
- For how many values of p, the circle x^{2}+y^{2}+2 x+4 y-p=0 and the coordinate axes have …
- Let f: \mathbb{R} \rightarrow \mathbb{R} be a differentiable function such that f(0)=0, f\…
- For a real number \alpha, if the system \[ \left[\begin{array}{ccc} 1 & \alpha & \alpha^{2…