I need help on these two questions QUICKLY! Thank you!!

Question #4 Zoe, Theresa, and Rafi are fifth graders who were asked to find the volume of a rectangular prism. Their conversation is shown below: Zoe: I counted the number of cubic units in the bottom layer of the prism. Then I added up all of the prism's layers together. Theresa: I computed the volume by multiplying length, width, and height. We learned this method. Rafi: I found the area of the base of the prism, and then multiplied that area by the prism's height. I thought about stacking the base up and up but multiplied rather than added. How are all three methods similar? Question #5 A rectangular prism made is 3 units high, 2 units wide, and 5 units long. What is its surface area in square units? Explain or show your reasoning