Calculate the number 399
NUMBERMANIA: Calculate the number 399 using numbers [4, 2, 7, 4, 22, 670] and basic arithmetic operations (+, -, *, /). Each of the numbers can be used only once.Correct answers: 2
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PhantoscopeIn 1895, the Phantoscope, an early motion picture projector that enlarged film images for viewing by large groups, was patented by Charles Francis Jenkins (No. 536,569). The Phantascope was designed jointly by C. Francis Jenkins and Thomas Armat, and shown at the Cotton States Exposition in Atlanta, Ga. in October 1895. Armat sold his rights to Thomas Edison, who marketed the invention. The Phantascope, modified by Armat, became the basis of Edison's Vitascope projector. These developments owed much to George Eastman's invention of roll film, followed by transparency film, that enabled the same camera to make multiple photographs in a series. |