8th Class Mathematics Direct and Inverse Proportions Question Bank

done Direct & Inverse Proportional (Time & Work) Total Questions - 30

• question_answer1)
  If x persons working x hours a day for each of y days produce y units of works, then the unit of work produced by y persons working y hours a day for each of x days is
  A)
   \[{{y}^{2}}/{{x}^{2}}\]                    done clear
  B)
   \[{{y}^{{}}}/{{x}^{2}}\]           done clear
  C)
   \[{{y}^{2}}/{{x}^{3}}\]                    done clear
  D)
   \[{{y}^{2}}/x\] done clear
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• question_answer2)
    Ravi and Sonu can do a job alone in 20 days and 30 days respectively. In how many days the job will be finished, if they work together?
  A)
   10 days              done clear
  B)
   12 days      done clear
  C)
   8 days                          done clear
  D)
   13 days done clear
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• question_answer3)
  In 4 men reap 40 acres in 30 days. How many acres will 18 men reap in 12 days?
  A)
   70                                done clear
  B)
   72       done clear
  C)
   60                    done clear
  D)
   68 done clear
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• question_answer4)
  A and B can do a work in 72 days. B and C in 120 days. A and C in 90 days. In how many days can A alone do the work?
  A)
   80                                done clear
  B)
   100             done clear
  C)
   110                              done clear
  D)
   120 done clear
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• question_answer5)
  Robert can finish the writing of the book in 8 days while James can finish the same work in 10 days. If they work together, then how long they will take to finish the same work?
  A)
   \[10\frac{1}{2}\]days                done clear
  B)
  \[6\frac{2}{3}days\]         done clear
  C)
   \[\frac{4}{9}\] days                   done clear
  D)
   \[4\frac{4}{9}\]days done clear
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• question_answer6)
  Two pipes A and B can fill a tank in 16 hours and 20 hours respectively. If both the pipes are opened simultaneously, how much time will be taken to fill the tank?
  A)
   \[8\frac{8}{5}\]hours                 done clear
  B)
   \[8\frac{8}{9}\] hours     done clear
  C)
   \[8\frac{17}{9}\]hours               done clear
  D)
   \[8\frac{7}{9}\]hours done clear
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• question_answer7)
  If 40 men can complete a work in 10 days working 10 hours a day, then find the number of men is required the work in 5 days if they work 10 hours in a day.
  A)
   100 men           done clear
  B)
   60 men   done clear
  C)
   150 men                       done clear
  D)
   80 men done clear
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• question_answer8)
  A is twice as good work man as B and together they finish a piece of work in 18 days. In how many days will A alone finish the work?
  A)
   27 days     done clear
  B)
   28 days          done clear
  C)
   30 days                        done clear
  D)
   31 days done clear
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• question_answer9)
  A can do a certain job in 12 days. B is 60% more efficient than A. How many days does B alone take to do the same job?
  A)
   \[9\,\,{\scriptstyle{}^{1}/{}_{2}}\]days             done clear
  B)
   \[8\,\,{\scriptstyle{}^{1}/{}_{2}}\] days         done clear
  C)
   \[7\,\,{\scriptstyle{}^{1}/{}_{2}}\] days   done clear
  D)
   \[11\,\,{\scriptstyle{}^{1}/{}_{2}}\] days done clear
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• question_answer10)
  A and B undertake to do a piece of work for Rs. 600. A alone can do it in 6 days while B alone can do it in 8 days but with the help of C, they finish it in 3 days. Find the share of C.
  A)
   Rs. 75   done clear
  B)
   Rs. 90           done clear
  C)
   Rs. 110                         done clear
  D)
   Rs. 85 done clear
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• question_answer11)
  A and B working separately can do a piece of work in 9 and 12 days respectively. If they work on alternate days beginning with A, then in how many days, the work will be completed?
  A)
   \[11{\scriptstyle{}^{1}/{}_{4}}\]days                done clear
  B)
   \[5{\scriptstyle{}^{1}/{}_{4}}\] days done clear
  C)
   \[\text{9}{\scriptstyle{}^{1}/{}_{4}}\] days                   done clear
  D)
   \[\text{10}{\scriptstyle{}^{1}/{}_{4}}\] days done clear
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• question_answer12)
  A, B and C can complete a piece of work in 24, 6 and 12 days respectively. Working together they will complete the same work in
  A)
   \[\frac{1}{24}\]days                  done clear
  B)
   \[\frac{7}{24}\]days          done clear
  C)
   \[3\frac{3}{7}\]days done clear
  D)
   4 days done clear
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• question_answer13)
  2 men and 3 boys can do a piece of work in 10 days. While 3 men and 2 boys can do the same work in 8 days. In how many days can 2 men and 1 boy do the work?
  A)
   \[12{\scriptstyle{}^{1}/{}_{2}}\]days  done clear
  B)
   \[13{\scriptstyle{}^{1}/{}_{2}}\] days done clear
  C)
   \[14{\scriptstyle{}^{1}/{}_{2}}\] days               done clear
  D)
   \[17{\scriptstyle{}^{1}/{}_{2}}\] days done clear
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• question_answer14)
  45 men can complete a work in 16 days. Six days after they started working, 30 more men joined them. How many days will they now take to complete the remaining work?
  A)
   5 days                          done clear
  B)
   6 days    done clear
  C)
   7 days                          done clear
  D)
   8 days done clear
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• question_answer15)
  X can do \[1/4\] of a work in 10 days. Y Can do 40% of the work in 40 days and Z can do 1/3 of the work in 13 days. Who will complete the work first?
  A)
   X                                 done clear
  B)
   Y               done clear
  C)
   Z        done clear
  D)
   X and Z both done clear
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• question_answer16)
  A and B can do a work in 12 days. B and C in 15 days. C and A in 20 days. If A, B and C work together, they will complete the work in
  A)
   5 days                          done clear
  B)
   \[7\frac{5}{6}\]days         done clear
  C)
   10 days   done clear
  D)
   \[15\frac{2}{3}\]days done clear
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• question_answer17)
  A can do a certain work in the same time in which B and C together can do it. If A and B together could do it in 10 days and C alone in 50 days , then B alone could do it in
  A)
   15 days            done clear
  B)
   20 days         done clear
  C)
   25 days done clear
  D)
   30 days done clear
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• question_answer18)
  A is thrice as good a work man as B and therefore is able to finish a job in 60 days less than B, working together they can do it in:
  A)
   20 days            done clear
  B)
   \[22\frac{1}{2}\] days       done clear
  C)
   25 days                        done clear
  D)
   30 days done clear
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• question_answer19)
  A can do a work in 15 days and B in 20 days. If they work on it together for 4 days, then the fraction of work that is left is:
  A)
   \[1/4\]              done clear
  B)
   1 /10           done clear
  C)
   7/15                             done clear
  D)
   8/15 done clear
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• question_answer20)
  A can finish a work in 24 days, B in 9 days and C in 12 days. B and C start the work but are forced to leave after 3 days. The remaining work was done by A in
  A)
   5 days                          done clear
  B)
   6 days          done clear
  C)
   10 days done clear
  D)
   \[10\frac{1}{2}\] days done clear
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• question_answer21)
  Two pipes A and B can fill a tank in 24 hours and 30 hours respectively. The tank is emptied. How much time will be taken by them to fill it?
  A)
   13 hours 20 min. done clear
  B)
   16 hours 30 min. done clear
  C)
   14 hours 10 min.           done clear
  D)
   15 hours 40 min. done clear
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• question_answer22)
  A pipe can fill a tank in 15 hours. Due to leak in the bottom, it is filled in 20 hours. If the tank is full, how much time will the leak take to empty ti ?
  A)
   120 hours                     done clear
  B)
   80 hours         done clear
  C)
   40 hours           done clear
  D)
   60 hours done clear
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• question_answer23)
  Pipes A and B can fill a tank in 6 hours and 9 hours respectively while another outlet pipe can empty it in 12 hours. If all the pipes are opened together in the empty tank, in how much time will it be full.
  A)
   \[5\frac{1}{7}\]hours     done clear
  B)
   \[6\frac{1}{7}\] hours        done clear
  C)
   \[8\frac{1}{7}\]hours                 done clear
  D)
   \[10\frac{1}{7}\]hours done clear
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• question_answer24)
  Two pipes A and B can fill a tank in 24 min. and 32 minutes respectively. If both the pipes are opened together, after how much time B should be closed so that the tank is full in 18 minutes.
  A)
   7 minutes                      done clear
  B)
   6 minutes         done clear
  C)
   8 minutes   done clear
  D)
   9 minutes done clear
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• question_answer25)
  Two pipes A and B can fill a tank in 2 hours and 75 minutes respectively. There is also an outlet C. If all the three pipes are opened together then the tank is full in 50 minutes. How much time will be taken by C alone to empty the full tank?
  A)
   90 minutes       done clear
  B)
   10 hours done clear
  C)
   150 minutes                  done clear
  D)
   120 minutes done clear
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• question_answer26)
  Two pipes can fill a cistern in 14 hours and 16 hours respectively. The pipes are opened simultaneously and it is found that due to leakage in the bottom it took 32 min. more to fill the cistern. When the cistern is full, in what time will the leak empty it?
  A)
   100 hours         done clear
  B)
   111 hours done clear
  C)
   112 hours   done clear
  D)
   114 hours done clear
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• question_answer27)
  Twenty women can do work in sixteen days. Sixteen men can complete the same work in fifteen days. What is the ratio between the capacity of a man and a woman?
  A)
   3 : 4                             done clear
  B)
   4 : 3 done clear
  C)
        5 : 3                             done clear
  D)
   data inadequate done clear
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• question_answer28)
  A, B and C can do a piece of work in 20, 30 and 60 days respectively. In how many days can A do the work if he is assisted by B and C on every 3rd day?
  A)
   12 days            done clear
  B)
   15 days   done clear
  C)
   16 days            done clear
  D)
   18 days done clear
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• question_answer29)
  A alone can complete a work in 16 days and B alone in 12 days. Starting with A, they work on alternate days. The total work will be complete in
  A)
   12 days            done clear
  B)
   13 days   done clear
  C)
   \[13\frac{5}{7}\]days                done clear
  D)
   \[13\frac{3}{4}\]days done clear
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• question_answer30)
  A can do a piece of work in 7 days by working 9 hours on each day and b can do it in 6 days by working 7 hours on each day. How long will they take to do it, working together for \[8\frac{2}{5}\] hours a day?
  A)
   4 days                          done clear
  B)
   3 days done clear
  C)
   2 days                          done clear
  D)
   5 days done clear
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