If the lines $x + 2ay + a = 0$, $x + 3by + b = 0$  and $x + 4cy + c = 0$ are concurrent, then $a$, $b$ and $c$ are in

  • A

    $A.P.$

  • B

    $G.P.$

  • C

    $H.P.$

  • D

    None of these

Similar Questions

If the system of equations $\alpha x+y+z=5, x+2 y+$ $3 z=4, x+3 y+5 z=\beta$ has infinitely many solutions, then the ordered pair $(\alpha, \beta)$ is equal to:

  • [JEE MAIN 2022]

Let $\alpha, \beta$ and $\gamma$ be real numbers. consider the following system of linear equations

$x+2 y+z=7$

$x+\alpha z=11$

$2 x-3 y+\beta z=\gamma$

Match each entry in List - $I$ to the correct entries in List-$II$

List - $I$ List - $II$
($P$) If $\beta=\frac{1}{2}(7 \alpha-3)$ and $\gamma=28$, then the system has ($1$) a unique solution
($Q$) If $\beta=\frac{1}{2}(7 \alpha-3)$ and $\gamma \neq 28$, then the system has ($2$) no solution

($R$) If $\beta \neq \frac{1}{2}(7 \alpha-3)$ where $\alpha=1$ and $\gamma \neq 28$,

then the system has

($3$) infinitely many solutions
($S$) If $\beta \neq \frac{1}{2}(7 \alpha-3)$ where $\alpha=1$ and $\gamma=28$, then the system has ($4$) $x=11, y=-2$ and $z=0$ as a solution
  ($5$) $x=-15, y=4$ and $z=0$ as a solution

Then the system has

  • [IIT 2023]

The value of $\left| {\begin{array}{*{20}{c}}
{\sin \alpha }&{\cos \alpha }&{\sin \left( {\alpha  + \gamma } \right)}\\
{\sin \beta }&{\cos \beta }&{\sin \left( {\beta  + \gamma } \right)}\\
{\sin \delta }&{\cos \delta }&{\sin \left( {\gamma  + \delta } \right)}
\end{array}} \right|$ is 

If $\left| {\,\begin{array}{*{20}{c}}a&b&c\\m&n&p\\x&y&z\end{array}\,} \right| = k$, then $\left| {\,\begin{array}{*{20}{c}}{6a}&{2b}&{2c}\\{3m}&n&p\\{3x}&y&z\end{array}\,} \right| = $

If $AB = A$ and $BA = B$, then