1. The problem statement, all variables and given/known data A swimming pool is 20 feet wide, 40 feet long, 3 feet deep at the shallow end and 9 feet deep at its deepest point. If the pool is being filled at a rate of 0.8 feet^3/min, how fast is the water level rising when the depth at the deepest point is 5 feet? 2. Relevant equations I believe the formula for volume of a swimming pool is V = lw((h+H/2)) where h is the shallowest depth and H is the deepest depth? Not 100% sure 3. The attempt at a solution I know that dV/dt = 0.8 ft^3/minute. The dimensions of the pool (20 by 40 ft) are constant and do not change. h can be expressed in terms of H (H/3) and subbed into the equation. I need to find dH/dt when H=5 feet. Other than this I'm completely stuck! Thanks for any help!