It seems that Google was recently seen testing homework practice problems and quizzes, all of which appear in the search results. When doing searches on certain types of queries, such as [physics], it would show a question and multiple choice answers for users. They would even get a hint as an option if they need help.
This test must only be for certain areas, as I was unable to get the practice problems/quizzes to work as of the time of this writing.
According to Google, this feature is “an experiment we’re running,” so that would explain why I, as an example, why I wasn’t seeing this pop up when queries were entered for me.
Source – Search Engine Land