Do you know the answer now? I am just trying to do some math problems. Not sure of the answer. Please post your answer.
1. current marginal price as function of time is (-1000 demand/day)($0.00001/demand)=-$0.01/day
2. 5000 demand/dayx$0.0001/demand=$0.05/day
current marginal revenue is$0.05-$0.01=$0.04