The solution set of a pair of equations $x+y-1=0$ and $2x+2y-2=0$ is $\ldots \ldots \ldots \ldots$

Do the following equations represent a pair of coincident lines? Justify your answer.
$3x + \frac{1}{7}y = 3$
$7x + 3y = 7$

On comparing the ratios $\frac{a_{1}}{a_{2}}, \frac{b_{1}}{b_{2}}$ and $\frac{c_{1}}{c_{2}},$ find out whether the lines representing the following pairs of linear equations intersect at a point,are parallel,or are coincident:
$5x - 4y + 8 = 0$
$7x + 6y - 9 = 0$

Two rails are represented by the equations $x + 2y - 4 = 0$ and $2x + 4y - 12 = 0$. Will the rails cross each other?

Do the following equations represent a pair of coincident lines? Justify your answer.
$\frac{x}{2} + y + \frac{2}{5} = 0$
$4x + 8y + \frac{5}{16} = 0$

The cost of $2\, kg$ of apples and $1\, kg$ of grapes on a day was found to be ₹ $160$. After a month,the cost of $4\, kg$ of apples and $2\, kg$ of grapes is ₹ $300$. Represent the situation algebraically and geometrically.