The total cost of $7$ pens and $5$ pencils is Rs. $50$,and the total cost of $5$ pens and $7$ pencils is Rs. $46$. Represent this as a pair of linear equations in two variables.

Draw the graphs of the lines $x=-2$ and $y=3$. Write the vertices of the figure formed by these lines,the $x$-axis and the $y$-axis. Also,find the area of the figure.

$A$ 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 $Rs.$).

Draw the graphs of the pair of linear equations $x+3y=6$ and $2x-3y=12$. Determine the coordinates of the vertices of the triangle formed by these linear equations and the $Y$-axis.

Five years ago,the sum of the ages of four persons was $60$ years. The sum of the present ages of those four persons is $\ldots \ldots \ldots \ldots$ years.

Five years ago,the sum of the ages of five persons was $50$ years. After five years,the sum of the ages of those five persons will be $\ldots \ldots \ldots \ldots$ years.