MATH PUZZLE: Can you replace...
MATH PUZZLE: Can you replace the question mark with a number?Correct answers: 207
The first user who solved this task is Rutu Raj.
#brainteasers #math #riddles
Frederick Scott ArcherDied 2 May 1857 (born 1813).English inventor of the wet-collodian process, the first practical photographic process which enabled making additional copies of a picture, that was used from 1851 until about 1880. While serving as a silversmith's apprentice, he transferred his interest from sculpture and coin design to seeking an improve photographic process. By 1848, he had discovered that collodion, a solution of gun-cotton in ether, could make plates superior to either Henry Talbot's calotype or the daguerrotype. Although sensitivity required fresh preparation and use while still moist, this new “wet plate”photography was favoured for three decades. Having never patented his process, Archer made no commercial gain for his process, and was in poverty when he died.« |