Three students have to give a speech in class today. in how many different orders can they give their speech

Which of the symbols correctly relates the two numbers below check all that apply 6? 6

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

Ineed in figuring out this problem.