Judiyah is the proud new owner of a chair making business. She makes custom wood chairs. She sells her custom chairs for $150. The cost of rent and the expensive saws and equipment she bought add up to about $50 a chair. The wood she uses is
standard wood and the materials to make one chair cost about $30. She pays one worker to help her move the chairs into people's
home. Everytime she sells a chair, she pays this worker
$10 for the hour of work to transport the homemade chair.

What is judiyah’s cost of production ?