MCQ
The remainder, when $(15^{23} + 23^{23})$ is divided by $19$, is
  • A
    $4$
  • B
    $15$
  • $0$
  • D
    $18$

Answer

Correct option: C.
$0$
c
$E = (19 - 4)^{23} + (19 + 4)^{23}$

   $= 2 [19^{23} + ^{23}C_2 · 19^{21} · 4^2 + .......... + ^{23}C_{22} · 19 · 4^{22}]$

   $= 2 · 19 [19^{22} + ^{23}C_2 · 19^{20} · 4^2 + .........+ ^{23}C_{22} · 4^{22}]$

$\Rightarrow E$ is divisible by $19 \Rightarrow$ Remainder $= 0$

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

The number of values of $x$ in the interval $[0, 5\pi]$ satisfying the equation $3sin^2x\, \,-\,\, 7sinx + 2 = 0$ is
${{x + 1} \over {(x - 1)\,(x - 2)\,(x - 3)}} = $
$P(n): 2 \times 7n + 3 \times 5n - 5$ is divisible by:
The locus of the orthocentre of the triangle formed by the focal chord of the parabola $y^2 = 4ax$ and the normals drawn at its extremeties is
A measure of central location which splits the data set into two equal groups is called the:
In a single throw of two dice, the probability of obtaining a total of $7$ or $9$, is
For $n \in Z$ , the general solution of the equation

$(\sqrt 3  - 1)\,\sin \,\theta \, + \,(\sqrt 3  + 1)\,\cos \theta \, = \,2$ is

Coefficient of $x^{n-6}$ in the expansion $n\left[ {x - \left( {\frac{{^n{C_0}{ + ^n}{C_1}}}{{^n{C_0}}}} \right)} \right]\left[ {\frac{x}{2} - \left( {\frac{{^n{C_1}{ + ^n}{C_2}}}{{^n{C_1}}}} \right)} \right]\left[ {\frac{x}{3} - \left( {\frac{{^n{C_2}{ + ^n}{C_3}}}{{^n{C_2}}}} \right)} \right].....$ $ \left[ {\frac{x}{n} - \left( {\frac{{^n{C_{n - 1}}{ + ^n}{C_n}}}{{^n{C_{n - 1}}}}} \right)} \right]$ is equal to (where $n = n . (n -1) . (n -2).... 3.2.1$ )
Let the coefficients of the middle terms in the expansion of $\left(\frac{1}{\sqrt{6}}+\beta x\right)^{4},(1-3 \beta x)^{2}$ and $\left(1-\frac{\beta}{2} x\right)^{6}, \beta>0$, respectively form the first three terms of an $A.P.$ If $d$ is the common difference of this $A.P.$, then $50-\frac{2 d}{\beta^{2}}$ is equal to.
The coefficient of  $x^2$ in the expansion of the product $(2 -x^2)$. $((1 + 2x + 3x^2)^6 +(1 -4x^2)^6)$  is