For Group K the cost of attaining an educational level y is

C_k(y)=$2000y

and for Group M the cost of attaining that level is

C_m(y)=$4000y

Employees will be offered $30,000 if they have y < y*, where y* is an education threshold determined by the employer. They will be offered $90,000 if they have y>y*.

a) The highest level of y* that can be set and still have the high-productivity people choose to meet it is

b)The lowest level of y* that can be set and still have only the high-productivity people meet it is

Please give the work and explanation thank you.