Question: Finite symmetry groups such as the Mathieu groups are used in coding theory, which is in turn applied in error correction of transmitted data, and in CD players. Another application is differential Galois theory, which characterizes functions having antiderivatives of a prescribed form, giving group-theoretic criteria for when solutions of certain differential equations are well-behaved.u[›] Geometric properties that remain stable under group actions are investigated in (geometric) invariant theory.
Try to answer this question if possible: What is used for error correction of transferred data?
Answer: coding theory
Question: On August 18, 2011, the CRTC issued a decision that allows CBC's mandatory market rebroadcasting transmitters in analogue to remain on-air until August 31, 2012. Before that deadline, CBC's licence renewal process would take place and CBC's digital transition plans would be examined as part of that process. The requirement remains for all of CBC's full-power transmitters occupying channels 52 to 69 to either relocate to channels 2 to 51 or become low-power transmitters. In some cases, CBC has opted to reduce the power of existing transmitters to low-power transmitters, which will result in signal loss for some viewers.
Try to answer this question if possible: What was agreed upon by the CBC and CRTC as a fair date to extend the deadline to?
Answer: unanswerable
Question: The Berbers along the Barbary Coast (modern day Libya) sent pirates to capture merchant ships and hold the crews for ransom. The U.S. paid protection money until 1801, when President Thomas Jefferson refused to pay and sent in the Navy to challenge the Barbary States, the First Barbary War followed. After the U.S.S. Philadelphia was captured in 1803, Lieutenant Stephen Decatur led a raid which successfully burned the captured ship, preventing Tripoli from using or selling it. In 1805, after William Eaton captured the city of Derna, Tripoli agreed to a peace treaty. The other Barbary states continued to raid U.S. shipping, until the Second Barbary War in 1815 ended the practice.
Try to answer this question if possible:  What city did William Eaton befriend to end the first Barbary War?
Answer: unanswerable
Question: Incandescent light bulbs come in a range of shapes and sizes. The names of the shapes may be slightly different in some regions. Many of these shapes have a designation consisting of one or more letters followed by one or more numbers, e.g. A55 or PAR38. The letters represent the shape of the bulb. The numbers represent the maximum diameter, either in 1⁄8 of an inch, or in millimeters, depending on the shape and the region. For example, 63 mm reflectors are designated R63, but in the US, they are known as R20 (2.5 in). However, in both regions, a PAR38 reflector is known as PAR38.
Try to answer this question if possible: What is not different in some regions?
Answer:
unanswerable