Question
The remainder when $(2021)^{203}$ is divided by $7$ is

Answer

c
$(2021)^{2023}=(7 \lambda-2)^{2023}$

$={ }^{2023} C_{0}(7 A )^{2023}-\ldots{ }^{2023} C _{2023} 2^{2023}$

$=7 t -2^{2023}$

$\therefore-2^{2023}=-2 \times 2^{2022}$

$=-2 \times\left(2^{3}\right)^{674}$

$=-2(1+7 \mu)^{674}$

$=-(7 \alpha+2)$

$\Rightarrow \text { remainder }=-2 \text { or }+5$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

Let $\{x\}$ and $[x]$ denote the fractional part of $x$ and the greatest integer $\leq x$ respectively of a real number $x$. If $\int \limits_{0}^{n}\{x\} d x, \int \limits_{0}^{n}[x] d x$ and $10\left( n ^{2}- n \right),( n \in N , n >1)$ are three consecutive terms of a $G.P.$, then $n$ is equal to
Number of integral solutions to the equation $x+y+z=21$, where $x \geq 1, y \geq 3, z \geq 4$, is equal to $..........$.
Let $ABC = I$ then $tr(ABC + BCA + CAB)$ is (where order of matrices $A, B, C$ is $3$ and $tr(A)$ is sum of diagonal elements in $A$)
Let $S_n$ be the sum to n-terms of an arithmetic progression $3,7,11, \ldots \ldots$. . If $40<\left(\frac{6}{\mathrm{n}(\mathrm{n}+1)} \sum_{\mathrm{k}=1}^{\mathrm{n}} \mathrm{S}_{\mathrm{k}}\right)<42$, then $\mathrm{n}$ equals
If $\omega $ is a complex cube root of unity, then $225 + $${(3\omega + 8{\omega ^2})^2}$$ + {(3{\omega ^2} + 8\omega )^2} = $
The area bounded by the curves $y=|x-1|+|x-2|$ and $y =3$ is equal to
If the sum and product of four positive consecutive terms of a $G.P.$, are $126$ and $1296$, respectively, then the sum of common ratios of all such $GPs$ is $.........$.
Let a conic $\mathrm{C}$ pass through the point $(4,-2)$ and $\mathrm{P}(\mathrm{x}, \mathrm{y}), \mathrm{x} \geq 3$, be any point on $\mathrm{C}$. Let the slope of the line touching the conic $\mathrm{C}$ only at a single point $\mathrm{P}$ be half the slope of the line joining the points $P$ and $(3,-5)$. If the focal distance of the point $(7,1)$ on $C$ is $d$, then $12 \mathrm{~d}$ equals ...........
The remainder when $428^{2024}$ is divided by $21$ is $.......$
The coefficient of $x^{18}$ in the expansion of $\left(x^4-\frac{1}{x^3}\right)^{15}$ is $...........$.