Solution:
Now each is required to abate = 16/2 = 8 units
So then A1= A2 = 8
MAC1 = 3*8 = 24
MAC2 = 8
so as MAC1 not equals MAC2, so it is not cost effective solution.
so higher MAC firm should abate less , which is firm 1
& Lower MAC firm should abate more , which is firm 2