Which best describes the centroid of a triangle?

For f(x) = 3x+1 and g(x) = x2 - 6, find (g/f)(x)

What is the equation of a line passing through (-6,5) and having a slope of 1/3

Madeline takes her family on a boat ride. going through york canal, she drives 6 miles in 10 minutes. later on as she crosses stover lake, she drives 30 minutes at the same average speed. which statement about the distances is true?