Vertical Curve Problem in Fundamentals of Transportation, engineering homework help

only 1question with 5 parts:

A crest vertical curve has a stopping sight distance of 412.59 ft and a G1 of +3.34% and a G2 of -2.17%. The point of vertical intersection is located at station 21+77.07 and has an elevation of 123.45 ft.

a. What is the station for the point of vertical curvature? (enter you answer in feet, not stations)

b. What is the station for the point of vertical tangent? (enter you answer in feet, not stations)

c. What is the elevation of the point of vertical curvature?

d. What is the elevation of the point of vertical tangent?

e. What is the elevation of the highest point on the curve?