MATH PUZZLE: Can you replace...
MATH PUZZLE: Can you replace the question mark with a number?Correct answers: 143
The first user who solved this task is Nasrin 24 T.
#brainteasers #math #riddles
Telephone exchangeIn 1891, Almon B. Strowger was issued a U.S. patent for his electromechanical switch to automate a telephone exchange (No. 447,918). Strowger did not invent the idea of automatic switching (it was first invented in 1879 by Connolly and McTigthe) but Strowger was the first to put it to effective use. His selector used electromagnets and pawls to move a wiper (with contacts on the end) vertically and around a bank of many other contacts, able to make a connection with any one of them. Strowger formed his company, Strowger Automatic Telephone Exchange, in Oct 1891. |