Replace the question mark with a number
MATH PUZZLE: Can you replace the question mark with a number?Correct answers: 220
The first user who solved this task is Nebojša Čokorilo.
#brainteasers #math #riddles
Steam pumpIn 1844, Henry Rossiter Worthington (b. 17 Dec 1817, d. 17 Dec 1880) patented the independent single direct-acting steam power pump, an invention which laid the foundation of the entire pump industry. He was a U.S. mechanical engineer, and this invention solved the major steam-engine problem of supplying water to the boiler - even when the engine was shut down - and replaced hand-pumping to keep the boiler filled. He had several inventions leading to the perfection of the direct-acting steam power pump (1845-55), patented the duplex steam pump (1859), and built the first duplex waterworks engine, widely adopted and used for more than 75 years. He established a pump manufacturing plant, New York City, in 1859. |