InterviewSolution
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A, B and C can complete a work in 20, 24 and 30 days respectively. All three of them starts together but after 4 days A leaves the job and B left the job 6 days before the work was completed. C completed the remaining work alone. In how many days was the total work completed?1). 102). 123). 144). 16 |
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Answer» LET the total amount of work be X Work done by A is one day = X/20 Work done by B in one day = X/24 Work done by C in one day = X/30 A, B and C work together for 4 days, Work finished in four days = 4 × ((X/20) + (X/24) + (X/30)) = 4 × (6 + 5 + 4) × X / 120 This give the work finished in first four days = (1/2) × X B left the job 6 days before the work was finished, so C worked alone for 6 days Work done by C in 6 days is = 6 × X / 30 = X/5 Work done by (X/2) + (X/5) = (7 × X)/10 Work left = X - (7/10) × X = (3/10) × X This work is finished by B and C working together The work done by B and C in one day is = (X/24) + (X/30) = (9/120) × X Let B and C together work for N days then N × (9/120) × X = (3/10) × X This means N = 4 ∴ Total number of days = 4 + 4 + 6 = 14 |
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