$y$ years ago,the sum of the ages of five friends was $x$ years,then the sum of the present ages of them is $\ldots \ldots \ldots \ldots$ years.

While arranging the students of standard $X$ in rows,if two rows are reduced,then one more student has to be arranged in each of the remaining rows. If three more rows are formed,then one student has to be taken off from each of the previously arranged rows. Find the total number of students in the class.

Solve the following pair of linear equations in two variables using the graphical method: $2x + y = 7$ and $x - 2y = 6$.

The solution of $x+y-1=0$ and $2x+2y-2=0$ is ............

Obtain the solution of the following pair of equations by elimination method:
$\frac{11}{y} - \frac{7}{x} = 1, \, \frac{9}{y} - \frac{4}{x} = 6$; $x \neq 0, \, y \neq 0$

Subtraction of two numbers is $5$. If the larger number is $x$,then the smaller number is $y = \ldots \ldots \ldots \ldots$