Replace the question mark with a number
MATH PUZZLE: Can you replace the question mark with a number?Correct answers: 167
The first user who solved this task is Marjan Kelemen.
#brainteasers #math #riddles
Leo Hendrik BaekelandBorn 14 Nov 1863; died 23 Feb 1944 at age 80. Leo Henricus Arthur Baekeland was a Belgian-American industrial chemist who invented the first thermosetting plastic, Bakelite, that did not soften when heated. His first successful invention was Velox (in the 1890's), a photographic paper that could be used with artificial light rather than sunlight, which he sold in 1899 to George Eastman for $1 million. He then experimented to find a synthetic substitute for shellac, a useful insulator of wires in electric coils. Eventually, he was able to control heat and pressure for a formaldehyde-phenol reaction. By 1909, he displayed the world's first fully synthetic plastic, which could be used not only for insulators, but moulded into buttons, knobs and countless other items. With this patented product, he helped found the modern plastics industry.« |