Problem: Greece is a developed country with an economy based on the service (82.8%) and industrial sectors (13.3%). The agricultural sector contributed 3.9% of national economic output in 2015. Important Greek industries include tourism and shipping. With 18 million international tourists in 2013, Greece was the 7th most visited country in the European Union and 16th in the world. The Greek Merchant Navy is the largest in the world, with Greek-owned vessels accounting for 15% of global deadweight tonnage as of 2013. The increased demand for international maritime transportation between Greece and Asia has resulted in unprecedented investment in the shipping industry.
How much of the national economic output did the agricultural sector of Greece contribute in 2015?
The answer is the following: 3.9%

Problem: The AVL, created by the Valencian parliament, is in charge of dictating the official rules governing the use of Valencian, and its standard is based on the Norms of Castelló (Normes de Castelló). Currently, everyone who writes in Valencian uses this standard, except the Royal Academy of Valencian Culture (Acadèmia de Cultura Valenciana, RACV), which uses for Valencian an independent standard.
Who established the AVL?
The answer is the following: Valencian parliament

Problem: The ethnogenesis of the Greek nation is linked to the development of Pan-Hellenism in the 8th century BC. According to some scholars, the foundational event was the Olympic Games in 776 BC, when the idea of a common Hellenism among the Greek tribes was first translated into a shared cultural experience and Hellenism was primarily a matter of common culture. The works of Homer (i.e. Iliad and Odyssey) and Hesiod (i.e. Theogony) were written in the 8th century BC, becoming the basis of the national religion, ethos, history and mythology. The Oracle of Apollo at Delphi was established in this period.
What national sporting event was held during this time period still goes on in celebration today ?
The answer is the following: the foundational event was the Olympic Games in 776 BC,

Problem: To understand groups beyond the level of mere symbolic manipulations as above, more structural concepts have to be employed.c[›] There is a conceptual principle underlying all of the following notions: to take advantage of the structure offered by groups (which sets, being "structureless", do not have), constructions related to groups have to be compatible with the group operation. This compatibility manifests itself in the following notions in various ways. For example, groups can be related to each other via functions called group homomorphisms. By the mentioned principle, they are required to respect the group structures in a precise sense. The structure of groups can also be understood by breaking them into pieces called subgroups and quotient groups. The principle of "preserving structures"—a recurring topic in mathematics throughout—is an instance of working in a category, in this case the category of groups.
What has to be compatible with the group operation?
The answer is the following:
constructions related to groups