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A And B Can Finish A Piece Of Work In 20 Days .b And C In 30 Days And C And A In 40 Days. In How Many Days Will A Alone Finish The Job ? |
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Answer» FIND ONE day work for all three (A+B)'s 1 day work = 1/20 ----(1) (B+C)'s 1 day work = 1/30 ----(2) and (C+A)'s 1 day work = 1/40 ----(3) 2(A+B+C) 1 day work = (1/20 + 1/30 + 1/40) => (A+B+C) = (6+4+3)/2*120 => (A+B+C) = 13/240 -----------(4) By eq. (2) and (4) A + 1/30 = 13/240 => A = 13/240 - 1/30 = (13-8)/240 = 1/48 then A's 1 day work = 1/48 so A alon can FINISH the job = 48 days Find one day work for all three (A+B)'s 1 day work = 1/20 ----(1) (B+C)'s 1 day work = 1/30 ----(2) and (C+A)'s 1 day work = 1/40 ----(3) 2(A+B+C) 1 day work = (1/20 + 1/30 + 1/40) => (A+B+C) = (6+4+3)/2*120 => (A+B+C) = 13/240 -----------(4) By eq. (2) and (4) A + 1/30 = 13/240 => A = 13/240 - 1/30 = (13-8)/240 = 1/48 then A's 1 day work = 1/48 so A alon can finish the job = 48 days |
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