SSC Sample Paper Mock Test-6 SSC CGL Tear-II Paper-1

  • question_answer
    40 men can complete a work in 40 days. They started the work together. But at the end of each 10th day 5 men left the job. The work would have been completed in

    A)  \[56\frac{2}{3}\]days

    B)                     \[53\frac{1}{3}\]days

    C)  52 days                       

    D)  50 days

    Correct Answer: A

    Solution :

    For the first 10 days 40 men worked.
    \[\therefore \] 40 men can complete the work in 40 days
    \[\therefore \] 1 man will complete the same work in 1600 days
    \[\therefore \]      1 man's 1 day's work \[=\frac{1}{1600}\]
    \[\therefore \] Part of work done in first 10 days \[=\frac{1}{4}\]
    For the next 10 days 35 men worked.
    Part of the work done \[=\frac{1\times 35\times 10}{1600}=\frac{7}{32}\]Parts
    For the next 10 days, 30 men worked
    Part of the work done \[=\frac{30\times 10}{1600}=\frac{3}{16}\]
    For the next 10 days, 25 men worked.
    Part of the work done \[=\frac{25\times 10}{1600}=\frac{5}{32}\]
    Similarly, part of the work done by 20 men in next 10 days \[=\frac{20\times 10}{1600}=\frac{1}{8}\]
    Work done to 50 days
    \[=\frac{1}{4}+\frac{7}{32}+\frac{3}{16}+\frac{5}{32}+\frac{1}{8}\]
    \[=\frac{8+7+6+5+4}{32}=\frac{30}{32}=\frac{15}{16}\]
    \[\therefore \] Remaining work \[=1-\frac{15}{16}=\frac{1}{16}\]
    Now 15 men remain to work 15 men's 1 day's work \[=\frac{15}{1600}\]
    \[\therefore \] Time taken to complete \[\frac{1}{16}\]part of work
    \[=\frac{1600}{15}\times \frac{1}{16}=\frac{20}{3}=6\frac{2}{3}\text{days}\]
    \[\therefore \]      Total time \[=50+6\frac{2}{3}=56\frac{2}{3}\text{days}\]


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