Calculate the number 787
NUMBERMANIA: Calculate the number 787 using numbers [4, 7, 4, 7, 10, 764] and basic arithmetic operations (+, -, *, /). Each of the numbers can be used only once.Correct answers: 3
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Carpet sweeper patentIn 1876, American inventor Melville (Reuben) Bissell (1843-89) received a U.S. patent for the carpet sweeper (No. 182,346). At his a crockery shop in Grand Rapids, Mich., his wife Anna's health was affected by dust from the packing materials. From a desperate need for self-preservation, he invented the carpet sweeper. They recognized the sweeper's marketing possibilities and began to assemble them in a room over the store. The inner workings and cases were made by women working in their homes. Tufts of hog bristles were bound with string, dipped in hot pitch, inserted in brush rollers and finally trimmed them with scissors. Anna Bissell gathered the parts together in clothes baskets and brought them back to the store for assembling. |