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.

Solve the following pair of linear equations by the method of substitution: $2x - y + 3 = 0$ and $y = 2x - \frac{3}{2}$.

The sum of the digits of a two-digit number is $9$. If $27$ is added to it,the digits of the number get reversed. The number is

$A$ fraction becomes $\frac{1}{4}$ if $2$ is subtracted from the numerator and $3$ is added to the denominator. If $6$ is added to the numerator and the denominator is multiplied by $3$,it becomes $\frac{2}{3}$. Find the fraction.

$x$ years ago,the age of Mahesh was $y$ years. Then,after $z$ years,his age will be $\ldots$ years.

Half the perimeter of a rectangular garden,whose length is $4 \, m$ more than its width,is $36 \, m$. Represent this as a pair of linear equations in two variables.