Question

Using the information given, calculate a grade to the nearest whole percent. The "rise" is 525 feet. If the scale on the map showed the "run" on the west side is 800 feet. The grade on the west side would be

The rise on the east side will still be 525 feet.

But, the scale shows the run is 1300 feet.

The grade on the east side would be

Answer 1

21/32, or 66%; and 21/52, or 40%.

Explanation:

Grade is the same as slope, which is rise/run.

For the west side, the rise is 525 and the run is 800; this gives us

525/800 = (525÷25)/(800/25) = 21/32 = 0.66 = 66%

For the east side, the rise is 525 and the run is 1300; this gives us

525/1300 = (525÷25)/(1300÷25) = 21/52 = 0.40 = 40%

Answer 2

The grade on the west side would be the vertical rise divided by the horizontal run or 525 divided by 800' or rounded off to 66% (a steep grade as in an underground mine a grade of 25% is considered very steep for vehicles to go up or conveyors to travel). On the east side the 40% grade was obtained by dividing the 525' vertical height by the 1300' run.