Replace the question mark with a number
MATH PUZZLE: Can you replace the question mark with a number?Correct answers: 140
The first user who solved this task is Roxana zavari.
#brainteasers #math #riddles
Dixon's lead pencilIn 1827, lead pencils were first manufactured by Joseph Dixon, who built his factory in Salem, Mass. Dixon was responsible for the development of the graphite industry in the U.S. In 1859 he patented graphite crucibles. When he died, the Joseph Dixon Crucible Company was the largest manufacturer of graphite products in the world. The first* pencil factory in the U.S. however, was started earlier by William Monroe of Concord, Mass., in Jun 1812. His first 30 pencils were bought by Benjamin Adams, a hardware dealer in Boston, Mass. The first pencils made in Great Britain* (1584) used graphite from Borrowdale, Cumberland. |