Threee individuals consume a public good, and their demands are expressed as:
P1=1.5-0.005Q(for Q<300)
P2=4.5-0.007Q(for Q<643)
P3=3.0-0.002Q(for Q<1500)
when P represents price in dollars per unit and Q represents putput in units perday. The marginal cost of providing the service is given as a constant $5.00 per unit. Determine the efficient level of output of this public good.