Answer:
Physical capital
Step-by-step explanation:
In the given question, it's given that a student can complete 50 math problems in 2 hours using pen and paper only. Using pen, paper, and a calculator, the same student can complete 100 math problems in 2 hours.
Physical capital refers to tangible and man-made objects that a company or a person can use to increase the output.
Here, as the person also uses a calculator in addition to paper and pen in the later case, so he was able to complete 100 math problems in 2 hours.