(Applications of Differentiation and Partial Derivatives). Answer the following. Choose the letter among the choices below. URGENT!!!Thankyou!

1. A. 10/3 inches B. 12 inches C. 15 inches D. 8 inches E. None of the Above
2. A. r= 4inches and h= 10/3 inches B. r= 6 inches and h= 5/3 inchesC. r= 8 inches and h= 14/3 inches D. r= 2inches and h=1/3 inches E. None
3. A. 28 B. 47 C. 51 D. 72 E. None of the Above
4. A. 28 B. 47 C. 51 D. 72 E. None of the Above
   

An open box is to be made from a 16-inch by 3--inch piece of cardboard by cutting out squares of equal size from the four corners and bending up the sides. What size should the squares be to obtain a box with the largest volume? Find the radius (r) and height (h) of the right circular cylinder of largest volume that can be inscribed in a right circular cone with radius 6 inches and height 10 inches. (The formula for the volume of the inscribed cylinder is V = mr h) Determine fr(1, 2) for the function f(x, y) = 2x y + 3x + 4y. Determine fy(1, 2) for the function f(x, y) = 2x y + 3x + 4y