HELP ME WITH THIS PRACTICE QUESTION!!! i dont understand

What is the size of the matrix resulting from

One card is dealt from a 52 card deck. find the probability that the dealt card is a 4 or a black 7

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