Find number abc
If a10a1 + 919ac = 1229b9 find number abc. Multiple solutions may exist.Correct answers: 21
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Electric plugIn 1904, the first U.S. patent for a separable electric attachment plug was issued to inventor and manufacturer Harvey Hubbell of Bridgeport, Connecticut (No. 774,250). One part adapted the Edison screw socket to provide its own double-slotted receptable now familiar throughout North America. Into it, a separate double flat-prong plug could be slipped. This solved the problem of twisted wires caused with a screw connection. Small slots reduced the chance of a dangerous shock. Thus, with a two-prong plug on any electric device, “electrical power in buildings may be utilized by persons having no electrical knowledge or skill.” On 11 Aug 1896 he had patented the pull-chain switch light socket (No. 565541). His manufacturing company,Harvey Hubbell Inc.exists today.« |