Question

A painter will paint n walls with the same size and shape in a building using a specific brand of paint. The painters fee can be calculated by the expression $nKAh$, where $n$ is the number of walls, $K$ is a constant with units of dollars per square foot, A is the length of each wall in feet and $h$ is the height of each wall in feet. If the customer asks the painter to use a more expensive brand of paint, which of the factors in the expression would change?

• A. $h$
• B. $l$
• C. $K$
• D. $n$

Answer 1

The correct option is C $K$

The painter’s fee is given by $nKAh$ where $n$is the number of walls, $K$is a constant with units of dollars per square foot, $A$ is the length of each wall in feet, and$h$is the height of each wall in feet.

Examining this equation shows that $A$ and $h$ will be used to determine the area of each wall. The variable $n$ is the number of walls, so $n$ times the area of the walls will give the amount of area that will need to be painted.

The only remaining variable is$K$, which represents the cost per square foot and is determined by the painter’s time and the price of paint.

Therefore,$K$is the only factor that will change if the customer asks for a more expensive brand of paint.