A 5' 6"-tall student casts a shadow 8 ft long at the same time a tree casts a 30-ft shadow. How tall is the tree? (Hint: The tree and its shadow are similar to the student and her shadow.)

Fred has a total of 62 dvd and cd. if the number of cd is three more than two times the number of dvd, how many cd does he have?

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

What is the total area of the figure?