Any idea on question b?

This is the number of parts out of 100, the numerator of a fraction where the denominator is 100. submit

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

Which one is the correct answer, and why?