For which values of $p$ does the pair of equations given below have a unique solution?
$4x + py + 8 = 0$
$2x + 2y + 2 = 0$

Champa went to a 'Sale' to purchase some pants and skirts. When her friends asked her how many of each she had bought,she answered,"The number of skirts is two less than twice the number of pants purchased. Also,the number of skirts is four less than four times the number of pants purchased". Help her friends to find how many pants and skirts Champa bought.

Draw the graphs of the equations $5x - y = 5$ and $3x - y = 3$. Determine the coordinates of the vertices of the triangle formed by these lines and the $y$-axis.

Solve by the method of substitution. Aftab tells his daughter,"Seven years ago,$I$ was seven times as old as you were then. Also,three years from now,$I$ shall be three times as old as you will be." Represent this situation algebraically.

Formulate the following problems as a pair of equations,and hence find their solutions:
Roohi travels $300 \ km$ to her home partly by train and partly by bus. She takes $4 \ hours$ if she travels $60 \ km$ by train and the remaining by bus. If she travels $100 \ km$ by train and the remaining by bus,she takes $10 \ minutes$ longer. Find the speed of the train and the bus separately.

Solve the following pairs of equations by reducing them to a pair of linear equations:
$\frac{10}{x+y} + \frac{2}{x-y} = 4$
$\frac{15}{x+y} - \frac{5}{x-y} = -2$