Final answer:
Ilary's opportunity cost of reading 90 pages of philosophy in terms of pages of astronomy cannot be determined without knowing her reading speed for astronomy. A PPF represents the trade-offs of producing various goods given limited resources. Increasing productivity shifts the PPF outward, allowing for more production.
Step-by-step explanation:
The student is asking about the concept of a Production Possibilities Frontier (PPF), which is a model used in economics that describes the trade-offs between producing different goods with limited resources. In this scenario, instead of countries, we have an individual, Ilary, who has a fixed amount of time to allocate between reading two subjects, economics and sociology.
Ilary's opportunity cost of reading 90 pages of philosophy can be understood if we also knew her reading speed for astronomy. Without this information, we are unable to provide an exact number of pages of astronomy. The opportunity cost is defined as the number of pages of astronomy forgone to read an additional number of pages of philosophy. This concept illustrates how improvements in resources or technology, such as having a calculator and a computer, can increase a person's productivity and shift the PPF outward, allowing for a higher production capacity.
Production efficiency is achieved when Ilary is operating on her PPF, meaning she is maximizing her resources and not able to produce more of one good without giving up some amount of the other. If she could increase her reading speed or extend her study hours, it would shift her PPF outward, similar to how a country can increase its production capabilities with more workers or better technology.