Binomial Theorem Questions (605)

If the coefficient of $x^{15}$ in the expansion of $\left(ax^3+\dfrac{1}{bx^{1/3}}\right)^{15}$ is equal to the coefficient of $x^{-15}$ in the expansion of $\left(ax^{1/3}-\dfrac{1}{bx^3}\right)^{15}$, where $a$ and $b$ are positive real numbers, then for each such ordered pair $(a,b)$:
If $a_n = \sum_{r=0}^{n} \frac{1}{C_r}$, then $\sum_{r=0}^{n} \frac{r^2}{C_r} = P(n)a_{n+2} + Q(n)a_{n+1} + a_n + R(n)$, where $P(n), Q(n), R(n)$ are the polynomial functions of $n$, then $P(5) =$
Let $K$ be the sum of the coefficients of the odd powers of $x$ in the expansion of $(1+x)^{99}$. Let $a$ be the middle term in the expansion of $\left(2+\dfrac{1}{\sqrt{2}}\right)^{200}$. If $\dfrac{{}^{200}C_{99}\,K}{a}=\dfrac{2^\ell\,m}{n}$, where $m$ and $n$ are odd numbers, then the ordered pair $(\ell,n)$ is equal to:
$(1+x)^n = \sum_{r=0}^{n} C_r x^r$
Let $n \in \mathbb{N}, n \geq 4$ and $P = \prod_{r=0}^{n} \, ^nC_r$, then:
Let $\sum_{r=0}^{200} a_r(1+x)^r = \sum_{r=0}^{200} b_r x^r$, where $a_r = 1$ ∀ $r ≥ 98$, then the greatest coefficient in the expansion of $(1+x)^{201}$ is :
In the expansion of $\left(z^2 + z^{-2}\right)^{15}$, the coefficients of the $8^{th}$ and $19^{th}$ terms are equal. The term independent of $z$ is given by
The number of different terms in the expansion of $(1 - z^{30})\left(1 + z + x^2\right)^{30}$ is
The coefficient of $x^4$ in the expansion of $(1 + x + x^2)^7$ is
The value of $\displaystyle\sum_{r=0}^{22}\,{}^{22}C_r\cdot{}^{23}C_r$ is:
If $a_n = \sum_{r=0}^{n} \frac{1}{C_r}$, then $\sum_{r=0}^{n} \frac{r^2}{C_r} = P(n)a_{n+2} + Q(n)a_{n+1} + a_n + R(n)$, where $P(n), Q(n), R(n)$ are the polynomial functions of $n$, then $Q(5) =$
Let $\left[(5+\sqrt{b})^n\right] = N$ where $b$, $n$ are natural numbers and $|5-\sqrt{b}|<1$. If $b$ and $n$ are picked randomly, then the probability that $N$ is odd belongs to the set (where $[\cdot]$ denotes the greatest integer function)
The value of x in the expression \(\left[x+x^{\log _{10}(x)}\right]^{5}\), if the third term in the expansion is 10,00,000, is
Let a and b are two positive real numbers such that a2 + b = 2, then the maximum value of term independent of x in the expansion of \(\left(a x^{\frac{1}{6}}+b x^{\frac{-1}{3}}\right)^{9}\) is:
The number of rational terms in the binomial expansion of \((\sqrt{2}+\sqrt[3]{3})^{18}\) is:
If x is positive, the first negative term in the expansion of \((1+x)^{\frac{27}{5}}\) is
The absolute difference of the coefficients of x10 and x7 in the expansion of \(\left(2 x^2+\frac{1}{2 x}\right)^{11}\) is equal to
If for some \(m, n ;{ }^{6} C_{m}+2\left({ }^{6} C_{m+1}\right)+{ }^{6} C_{m+2} \gt { }^{8} C_{3}\) and \({ }^{n-1} P_{3}:{ }^{n} P_{4}=1: 8\), then \({ }^{n} P_{m+1}+{ }^{n+1} C_{m}\) is equal to
The term independent of x in the expression of (1 - x2 + 3x3)\(\left(\frac{5}{2} x^3-\frac{1}{5 x^2}\right)^{11}\), x \(\neq\) 0 is
If $(1+x)^{2010}=C_0+C_1x+\cdots+C_{2010}x^{2010}$, then $C_2+C_5+C_8+\cdots+C_{2009}$ equals
The value of \(-{ }^{15} \mathrm{C}_1+2 .{ }^{15} \mathrm{C}_2-3 .{ }^{15} \mathrm{C}_3+\ldots\) \( -15 .{ }^{15} \mathrm{C}_{15}+{ }^{14} \mathrm{C}_1+{ }^{14} \mathrm{C}_3+{ }^{14} \mathrm{C}_5+\ldots +{ }^{14} \mathrm{C}_{11}\) is:
If C0, C1, C2, ..., Cn are the binomial coefficients, then 2\(\cdot\)C1 + 23\(\cdot\)C3 + 25\(\cdot\)C5 + ... equals
The greatest coefficient in the expansion of (1 + x)2n+2 is
If (1 + x)n = C0 + C1x + C2x2 + ... + Cnxn, then \(\frac{C_{1}}{C_{0}}+\frac{2 C_{2}}{C_{1}}+\frac{3 C_{3}}{C_{2}}+\ldots \frac{n C_{n}}{C_{n-1}}\) =
Let $\alpha=\displaystyle\sum_{r=0}^{n}(4r^2+2r+1)\binom{n}{r}$ and $\beta=\left(\displaystyle\sum_{r=0}^{n}\dfrac{\binom{n}{r}}{r+1}\right)+\dfrac{1}{n+1}$. If $140<\dfrac{2\alpha}{\beta}<281$, then the value of $n$ is _______.
The coefficient of $x^{1012}$ in the expansion of $(1+x^n+x^{253})^{10}$ where $n\leq22$ is any positive integer, is
If $\left(x - 2 + \dfrac{1}{x}\right)^{30} = a_0 x^{30} + a_1 x^{29} + \ldots + a_{29}x + a_{30} x^{-1} + \ldots + a_{60}x^{-30}$ and $k = a_0 + a_1 + \ldots + a_{60}$. If $k - a_{30} = -{}^nC_r$, then $n + r$ is equal to
Line \(L_{1}\) of slope 2 and line \(L_{2}\) of slope \(\frac{1}{2}\) intersect at the origin \(O\). In the first quadrant, \(P_{1}, P_{2}, \ldots ., P_{12}\) are 12 points on line \(L_{1}\) and \(Q_{1}\), \(Q_{2}, \ldots ., Q_{9}\) are 9 points on line \(L_{2}\). Then the total number of triangles, that can be formed having vertices at three of the 22 points \(O, P_{1}\), \(P_{2}, \ldots, P_{12}, Q_{1}, Q_{2}, \ldots ., Q_{9}\), is:
Let $\left[(5+\sqrt{b})^n\right] = N$ where $b$, $n$ are natural numbers and $|5-\sqrt{b}|<1$. If $b$ and $n$ are picked randomly, then the probability that $N$ is odd belongs to the set (where $[\cdot]$ denotes the greatest integer function)
Find the coefficient of the term independent of x in the expansion of \(\left(\dfrac{x+1}{x^{2/3} - x^{1/3} + 1} - \dfrac{x-1}{x - x^{1/2}}\right)^{10}\).
Given \( {}^{20}C_r \cdot {}^{20}C_0 + {}^{20}C_{r-1} \cdot {}^{20}C_1 + {}^{20}C_{r-2} \cdot {}^{20}C_2 + \cdots + {}^{20}C_0 \cdot {}^{20}C_r \), which equals \( {}^{40}C_r \). Find the value of \( r \) for which this expression is maximum.
If the sum of coefficients in the expansion of (1 + x3)n is p, that of (1 - 4x + 7x2)n is q and (1 - 5x + 10x2 + 2x3)n is r, then
The term independent of \(x\) in the binomial expansion of \(\left(1-\dfrac{1}{x}+3x^5\right)\left(2x^2-\dfrac{1}{x}\right)^8\) is
If the coefficient of 4th term in the expansion of (a + b)n is 56, then n is
The number of terms in the expansion of \(\left(1 - \dfrac{2}{x} + \dfrac{4}{x^2}\right)^n\) is \({}^{n+2}C_2 = 28\). Find the sum of coefficients of the expansion.
Given \((1-x)^2(1+x^2)^3(1+x^3)^4\) Find the coefficient of \(x^{10}\).
If $(1+x+x^2)^n=\sum_{r=0}^{2n}a_r x^r$, then $a_r-{}^nC_1 a_{r-1}+{}^nC_2 a_{r-2}-\cdots+(-1)^r{}^nC_r$ equals (r not multiple of 3)
The remainder when (11)1011 + (1011)11 is divided by 9 is
If \(10^n + 3 \cdot 4^{n+2} + k\) is divisible by 9 for all \(n \in \mathbb{N}\), then the least positive integral value of \(k\) is __________.
If the coefficient of $x^7$ in the expansion of $\left(ax^2 + \frac{1}{bx}\right)^{11}$ and coefficient of $x^{-7}$ in the expansion of $\left(ax - \frac{1}{bx^2}\right)^{11}$ are equal, then the minimum value of $a^2 + b^2$ is
Given \(S = 2\,{}^{20}C_0 + 5\,{}^{20}C_1 + 8\,{}^{20}C_2 + \cdots + 62\,{}^{20}C_{20}\), find the value of \(S\).
Consider: \((\sqrt{3}+1)^{2n} - (\sqrt{3}-1)^{2n}\). Which of the following is true?
If \((27)^{999}\) is divided by 7, then the remainder is
If $(1+x)^{2010}=C_0+C_1x+\cdots+C_{2010}x^{2010}$, then $C_2+C_5+C_8+\cdots+C_{2009}$ equals
If 93199 is divided by 162, the remainder is
If a is the remainder when 540 is divided by 11 and b is the remainder when 22011 is divided by 17, the value of a ⊕ b is
The sum of the real values of \(x\) for which the middle term in the binomial expansion of \(\left(\dfrac{x^3}{3} + \dfrac{3}{x}\right)^8\) equals 5670 is ___________.
Find \(a\) if the 17th and 18th terms of the expansion \((2 + a)^{50}\) are equal.
Find the 6th term in the expansion of \((2x^2 - 1/3x^2)^{10}\).
If the coefficients of \((r-5)\)th and \((2r-1)\)th terms in the expansion of \((1+x)^{34}\) are equal, find \(r\).