The slope is defined as rise/run - in other words, for every step you take horizontally, how many steps you should take vertically to get to a point on the same line.
In our case, the ladder rises 20 feet for every horizontal change of 4 feet; therefore, the slope is
[tex]\frac{\text{rise}}{\text{run}}=\frac{20ft}{4ft}[/tex]dividing 30 ft by 4 ft gives 5; therefore,
[tex]\frac{\text{rise}}{\text{run}}=5.[/tex]Hence, the correct answer to choose is A. 5.
