Problem: Comparison of a back-translation with the original text is sometimes used as a check on the accuracy of the original translation, much as the accuracy of a mathematical operation is sometimes checked by reversing the operation. But the results of such reverse-translation operations, while useful as approximate checks, are not always precisely reliable. Back-translation must in general be less accurate than back-calculation because linguistic symbols (words) are often ambiguous, whereas mathematical symbols are intentionally unequivocal.
What symbol set has the property of being unintentionally unequivocal?
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Answer: unanswerable


Problem: In 530 BC Cyrus the Great, King of the Persian Achaemenid Empire crossed the Hindu-Kush mountains to seek tribute from the tribes of Kamboja, Gandhara and the trans-India region (modern Afghanistan and Pakistan). By 520 BC, during the reign of Darius I of Persia, much of the northwestern subcontinent (present-day eastern Afghanistan and Pakistan) came under the rule of the Persian Achaemenid Empire, as part of the far easternmost territories. The area remained under Persian control for two centuries. During this time India supplied mercenaries to the Persian army then fighting in Greece.
What did India supply to the Persian war efforts against Greece?
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Answer: mercenaries


Problem: Antarctic explorers Robert Falcon Scott and Frank Bickerton both lived in the city. Artists include Beryl Cook whose paintings depict the culture of Plymouth and Robert Lenkiewicz, whose paintings investigated themes of vagrancy, sexual behaviour and suicide, lived in the city from the 1960s until his death in 2002. Illustrator and creator of children's series Mr Benn and King Rollo, David McKee, was born and brought up in South Devon and trained at Plymouth College of Art. Jazz musician John Surman, born in nearby Tavistock, has close connections to the area, evidenced by his 2012 album Saltash Bells. The avant garde prepared guitarist Keith Rowe was born in the city before establishing the jazz free improvisation band AMM in London in 1965 and MIMEO in 1997. The musician and film director Cosmo Jarvis has lived in several towns in South Devon and has filmed videos in and around Plymouth. In addition, actors Sir Donald Sinden and Judi Trott. George Passmore of Turner Prize winning duo Gilbert and George was born in the city, as was Labour politician Michael Foot whose family reside at nearby Trematon Castle.
Where did the creator of Mr Benn and King Rollo study?
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Answer:
Plymouth College of Art