If $(3,5)$ is a solution of the equation $2x + 5y = k$,find the value of $k$.

Express the following linear equation in the form $ax + by + c = 0$ and indicate the values of $a$,$b$,and $c$: $x = 3y$.

The total cost of a school picnic consists of two parts: a fixed bus fare of ₹ $200$ and the cost of snacks at the rate of ₹ $30$ per student. Representing the total number of students by $x$ and the total cost by $y$,form a linear equation in two variables. If the number of students going on the picnic is $40$,find the total cost.

Write whether the following statement is True or False. Justify your answer:
The graph given below represents the linear equation $x=3$.

Write four solutions for the following equation: $2x + 3y = 7$.

Write four solutions for the following equation: $5x + 3y = 16$.