Y = K/3L/3 a) Find the marginal product of labour (MPL). How does an increase in the amount of labour affect MPL? How does an increase in the amount of capital affect MPL? b) Find the marginal product of capital (MPK). How does an increase in the amount of labour affect MPK? How does an increase in the amount of capital affect MPK? c) When would the production function experience: increasing, decreasing or constant returns to scale? d) What is the income share paid to labour? What is the income share paid to capital?