Which explains whether or not the function represents a direct variation? a.) This function represents a direct variation because it passes through the origin and has a constant rate of change of $5 per hour.
b.) This function represents a direct variation because it has a positive, constant rate of change of $10 per hour.
c.) This function does not represent a direct variation because it does not represent the cost for 1 hour.
d.) This function does not represent a direct variation because the function rule for the cost is to add $10, not multiply by a constant.

The school track has eight lanes. each lane is 1.25 meters wide. the arc at each end of the track is 180. the distance of the home straight and the radii for the arcs in the 1st 4 lanes are given. s=85m r1=36.5m r2=37.75m r3=39m r4=40.25m part one: find the radii of lanes 5 through 8 of the track. show your work. part two: if max ran around lane one, how far did he run? show your work and explain your solution. part three: max wants to run a total of three laps around the track, choose two additional lanes (2-8) for him to run and find the distance around those two lanes. show your work and round to the hundredths. part 4: based on your lane choices in part three, what was the total distance max ran in the three laps around the track?