Two firms can control emissions at the following marginal costs: MC₁ = $200q₁, MC₂ = $100q₂, where q₁ and q₂ are, respectively, the amount of emissions reduced by the first and second firms. Assume that with no control at all, each firm would be emitting 20 units of emissions or a total of 40 units for both firms.

a. Compute the cost-effective allocation of control responsibility if a total reduction of 21 units of emissions is necessary.

b. Compute the cost-effective allocation of control responsibility if the ambient standard is 27 ppm, and the transfer coefficients that translate a unit of emissions into a ppm concentration at the receptor are, respectively, a₁ = 2. 0 and a₂ = 1. 0.