Which number should replace the question mark?FUNNY MATH: Which number should replace the question mark?
Correct answers: 30
The first user who solved this task is Sanja Šabović.
#brainteasers #math #riddles
Roy J. PlunkettBorn 26 Jun 1910; died 12 May 1994 at age 83.American chemist and inventor of Teflon (the DuPont trademark name for Polytetrafluoroethylene or PTFE). His discovery, while working for DuPont, was accidental. On 6 Apr 1938, Plunkett found that a tank of gaseous tetrafluoroethylene (CF2CF2) had polymerized to a white powder. It was patented on 4 Feb 1941. During WW II this new polymer was applied as a corrosion-resistant coating to protect metal equipment used in the production of radioactive material. DuPont released its trademarked Teflon coated nonstick cookware in 1960.