If the lines given by $3x + 2ky = 2$ and $2x + 5y + 1 = 0$ are parallel,then the value of $k$ is

The pair of equations $ax - y = 5$ and $4x - 2y = 10$ has an infinite number of solutions. Then $a = \ldots$

Solve the following pair of linear equations by the method of elimination:
$4x - 3y = 8$
$6x - y = \frac{29}{3}$

Solve the following pairs of equations by the method of elimination:
$9x + 7y = 55$
$7x + 9y = 57$

After $x$ years,the sum of the ages of Sachin and Sehwag will be $y$ years,then the sum of the ages before $3$ years was $\ldots \ldots \ldots \ldots$ years.

$A$ railway half ticket costs half the full fare,but the reservation charges are the same on a half ticket as on a full ticket. One reserved first class ticket from station $A$ to $B$ costs $Rs. 2530$. Also,one reserved first class ticket and one reserved first class half ticket from $A$ to $B$ costs $Rs. 3810$. Find the full first class fare from station $A$ to $B$,and also the reservation charges for a ticket (in $Rs.$).