$2 \le r \le n$ માટે,$\binom{n}{r} + 2\binom{n}{r-1} + \binom{n}{r-2}$ ની કિંમત શોધો.

$\frac{C_1}{C_0} + 2\frac{C_2}{C_1} + 3\frac{C_3}{C_2} + \dots + 15\frac{C_{15}}{C_{14}} = $

$\sum\limits_{k = 0}^{10} {^{20}{C_k} = }$

$z \in \mathbb{C}$ માટે,જો $(1+z)^n = 1 + { }^n C_1 z + { }^n C_2 z^2 + \ldots + { }^n C_n z^n$ અને $\sum_{r=0}^{100} { }^{100} C_r \sin(rx) = \left(2 \cos \frac{x}{2}\right)^{100} \sin(kx)$ હોય,તો $k =$

$\sum\limits_{r = 0}^{n - 1} {\frac{{^n{C_r}}}{{^n{C_r} + {\,^n}{C_{r + 1}}}}} $ નું મૂલ્ય શું થાય?

જો $n \in N$ માટે $(1+x)^n = C_0 + C_1 x + C_2 x^2 + \ldots + C_n x^n$ હોય,તો $C_0 + \frac{C_1}{2} + \frac{C_2}{3} + \ldots + \frac{C_n}{n+1} =$