1. The problem statement, all variables and given/known data Let l, w, and h be the length, width and height of a rectangular box. The length l is increasing with time at at rate of 1 m/s, while the width and the height are decreasing at rates 2 m/s and 1m/s respectively. At a certain moment in time the dimensions of the box are l=5, w=4m and h=3m. Find the rate of change of the volume of the box at this moment in time. Help please? 2. Relevant equations The rate of change is just the derivative, but I am not sure how to write it out with 3 variables, I'm kind of stuck from the beginning. Chain rule 3. The attempt at a solution I drew the box and labeled it l=5, w=4, h=3. I'm not sure how to proceed . . .