A firm undergoes a learning curve over its first few years

Question

A firm undergoes a learning curve over its first few years of existence

In its first year, its cost function is C(Q)= 128 + 3Q + 2q² with MC= 3 + 4Q

In its second year, its cost function is C(Q)= 100 + 2Q + q² with MC= 2 + 2Q

In its third year, its cost function is C(Q)= 64 + 2q² with MC= 2Q

In each year the firm produces at its MES.

(a) Work out the MES in each year.