Cost of production

A worker produces snowboards with a technology that can be represented by the production function . The price of capital is $10 per unit and the price of labor is $5 per unit.

Originally he is using 16 units of capital and 4 units of labor. How many snowboards does he produce?

What is his cost of production, and what does he spend on capital?

What is his optimal cost minimizing input mix for the output you found in part a?