Agranary is filled with 6000 kg of grain. the grain is shipped out at a constant rate of 1000 kg per month. storage costs equal 2 cents per kg per month. let s(t) be the total storage charge for t months. write a differential equation for s with 0 t6. solve the initial value problem for s(t). what is the total storage bill for 6 months? answer s( +120t s(6) 360(s)