If $n$ represents any integer, then which expression represents multiple of $4$ ?

The parking fee of a certain car park is as follows 

For the first hour: $₹10$, For every additional hour: $₹5$.

Frame an expression for the amount paid after $h$ $\mathrm{hours}$. Also find the actual amount paid after $3\frac{1}{2} \mathrm{hours}$.

Aditi's mother is renovating her kitchen. One of the walls of kitchen is entirely made up of tiles. She wants to have a row of floral designs made up of yellow and red hexagonal tiles in the middle of the wall as shown in the adjoining figure.

If there are $57$ flowers in a row, find out how many yellow-and red-coloured tiles she requires for that wall.

Write an algebraic expression for the following:

Half a number subtracted from $16$

Write an algebraic expression for the following:

$7$ added to the sum of $3$ and $x$

Write an algebraic expression for the following:

One more than twice a number $z$.

Write an algebraic expression for the following:

Thrice the sum of a number and $40$.

Write the general formula for the following pattern of houses made from matchsticks and hence deduce the number of matchsticks required to make $7$ such houses: