Answer:
The marginal product of capital (MPK) is

Explanation:
Data provided in the question:
The firm's Cobb-Douglas production function is given as
⇒ Q =

Now,
To find the marginal product of capital (MPK) computing the partial derivation of the Cobb-Douglas production function
i.e

here, term L will be constant as it is a partial derivation with respect to K
thus,

or

or

Hence,
the marginal product of capital (MPK) is
