The Length L, Width W and Height H of a Box

Short Answer

The length l, width w and height h of a box change with time. At a certain instant the dimensions are $l = 4$ and $w = h = 6$ , and l and w are increasing at a rate of 10 m/s while h is decreasing at a rate of 1 m/s. At that instant find the rates at which the surface area is changing.