London has a diverse range of peoples and cultures, and more than 300 languages are spoken within Greater London. The Office for National Statistics estimated its mid-2014 population to be 8,538,689, the largest of any municipality in the European Union, and accounting for 12.5 percent of the UK population. London's urban area is the second most populous in the EU, after Paris, with 9,787,426 inhabitants according to the 2011 census. The city's metropolitan area is one of the most populous in Europe with 13,879,757 inhabitants,[note 4] while the Greater London Authority states the population of the city-region (covering a large part of the south east) as 22.7 million. London was the world's most populous city from around 1831 to 1925.
As of mid-2014, London's population forms what percentage of the entire United Kingdom population?
12.5

Melbourne's CBD, compared with other Australian cities, has comparatively unrestricted height limits and as a result of waves of post-war development contains five of the six tallest buildings in Australia, the tallest of which is the Eureka Tower, situated in Southbank. It has an observation deck near the top from where you can see above all of Melbourne's structures. The Rialto tower, the city's second tallest, remains the tallest building in the old CBD; its observation deck for visitors has recently closed.
Which tower is Melbourne's second tallest?
The Rialto

In mathematics, the Persian mathematician Muhammad ibn Musa al-Khwarizmi gave his name to the concept of the algorithm, while the term algebra is derived from al-jabr, the beginning of the title of one of his publications. What is now known as Arabic numerals originally came from India, but Muslim mathematicians did make several refinements to the number system, such as the introduction of decimal point notation. Sabian mathematician Al-Battani (850-929) contributed to astronomy and mathematics, while Persian scholar Al-Razi contributed to chemistry and medicine.
Where did Arabic numerals originate?
India