Download App

STD 11 - 6. permutation and combination — JEE STD 11 Science — Question

Gujarat BoardEnglish MediumSTD 11 ScienceJEESTD 11 - 6. permutation and combination4 Marks
Question
In a multiple- choice test consisting of $8$ questions, each question has four options. For each of the questions, exactly one of the four options is the right answer.$A$ student answers all the questions by choosing one option for each question. The number of ways in which the student can get exactly $5$ correct answers is
✓

Answer

d
(d)

Each question can be answered in 4 different ways

Required number of ways

$={ }^8 C _5 \times(1) \times(3)^3$

$=1512$

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

Explore more

JEE STD 11 Science question papers→Gujarat Board STD 11 Science question papers→Gujarat Board question paper generator→

Similar questions

${{\sqrt {6 + 2\sqrt 3 + 2\sqrt 2 + 2\sqrt 6 } - 1} \over {\sqrt {5 + 2\sqrt 6 } }}$
→
If the shortest distance between the lines $\frac{x+2}{2}=\frac{y+3}{3}=\frac{z-5}{4}$ and $\frac{x-3}{1}=\frac{y-2}{-3}=\frac{z+4}{2}$ $\frac{38}{3 \sqrt{5}} k$ and $\int_0^k\left[x^2\right] d x=\alpha-\sqrt{\alpha},$ denotes the greatest integer function, then $6 \alpha^3$ is equal to $............$
→
First term of the ${11^{th}}$ group in the following groups $(1), (2, 3, 4), (5, 6, 7, 8, 9),……….$ is
→
The line $x + y = p$ meets the axis of $x\, \& \,y$ at $A\, \& \,B$ respectively . A triangle $APQ$ is inscribed in the triangle $OAB$, $O$ being the origin, with right angle at $Q . P$ and $Q$ lie respectively on $OB$ and $AB$ . If the area of the triangle $APQ$ is $3/8^{th}$ of the area of the triangle $OAB$, then $\frac{{A\,Q}}{{B\,Q}}$ is equal to :
→
The coefficient of $x$ in the expansion of ${[\sqrt {1 + {x^2}} - x]^{ - 1}}$ in ascending powers of $x$, when $|x| < 1$, is
→
The number of solution pairs $(x, y)$ of the simultaneous equations $\log _{1 / 3}(x+y)+\log _3(x-y)=2$ $2^{y^2}=512^{x+1}$ is
→
The complex number $z$ satisfies the condition  $\left| {z - \frac{{25}}{z}} \right| = 24.$ The maximum distance from the origin of coordinates to the point $z$ is :-
→
If $a$ and $b$ are the roots of equation $x^2-7 x-1=0$, then the value of $\frac{a^{21}+b^{21}+a^{17}+b^{17}}{a^{19}+b^{19}}$ is equal to $........$.
→
Let $n$ be the number of ways in which $5$ boys and $5$ girls can stand in a queue in such a way that all the girls stand consecutively in the queue. Let $m$ be the number of ways in which $5$ boys and $5$ girls can stand in a queue in such a way that exactly four girls stand consecutively in the queue. Then the value of $\frac{m}{n}$ is
→
Let the mean and the variance of $20$ observations $x_{1}, x_{2}, \ldots x_{20}$ be $15$ and $9 ,$ respectively. For $\alpha \in R$, if the mean of $\left( x _{1}+\alpha\right)^{2},\left( x _{2}+\alpha\right)^{2}, \ldots,\left( x _{20}+\alpha\right)^{2}$ is $178 ,$ then the square of the maximum value of $\alpha$ is equal to $...........$
→