What is the change in grade for a 30-foot long driveway with a 5% slope?

To determine the change in grade for a driveway that is 30 feet long with a 5% slope, you can use the formula for calculating the vertical rise based on the slope percentage and horizontal distance. The slope percentage indicates how many inches of rise there is for every 100 inches of horizontal distance.

In this case, a 5% slope means that for every 100 feet horizontally, the vertical change is 5 feet. Since we are dealing with a 30-foot long driveway, we can calculate the vertical change using the following steps:

1. Convert the slope percentage to a decimal: 5% = 0.05.

2. Multiply the length of the driveway by the slope to find the change in grade:

Change in grade = 30 feet * 0.05 = 1.5 feet.

3. Convert the change in feet to inches: 1.5 feet * 12 inches/foot = 18 inches.

Therefore, the correct change in grade for a 30-foot long driveway with a 5% slope is 18 inches, aligning with the correct answer choice.