Aroad has a 10% grade. 1. what is the angle of elevation of the road? 2. if the road is 2km long, how much does it rise?

1.  m = rise/run
m = 10/100 = 0.1
tan α = 0.1
α = tan^(-1) 0.1 
α = 5.71 °
2. 2 km = 2,000 m
 x² + ( 0.1 x )² = 2,000²
 x² + 0.01 x² = 4,000,000
 1.01 x² = 4,000,000
 x = 1,990 m
 h = 1,990 m * 0.1
 h = 199 m
 The road rises 199 m.

When rates are expressed as a quantity of 1, such as 2 feet per second or 5 miles per hour, they are called unit rates. if you have a multiple-unit rate such as 120 students for every 3 buses, and want to find the single-unit rate, write a ratio equal to the multiple-unit rate with 1 as the second term.