Can you have a zero displacement and a non zero average velocity

Find the volume of the described solid.the solid lies between planes perpendicular to the x-axis at x = 0 and x=7. the cross sectionsperpendicular to the x-axis between these planes are squares whose bases run from the parabolay=-31x to the parabola y = 30/x.a) 441b) 147c) 864d) 882

We just started the introduction into circles and i have no idea how to do this.

Landon wrote that 3−2.6=4. which statement about his answer is true?