Time and work Exercise

Abhishek Jain

1. A takes twice as much time as B and C takes thrice as much time as B to finish a work. Working together, they can finish the work in 12 days. Find the number of days needed for A to go the work alone Ans: 44 2. 6 boys can complete a piece of work in 16 h. In how many hours will 8 boys complete the same work? Ans: 12 3. A is thrice as good a workman as B and therefore is able to finish a job in 30 days less than B. How many days will they take to finish the job working together? Ans: 11 4. 5 men start working to complete a work in 15 days. After 5 days, 10 women are accompanied by them to complete the work in next 5 days. If the work is to be done by women only, when could the work be over, if 10 women have started it? Ans: 15 days 5. A and B together can complete a work in 3 days. They started together but after 2 days, B left the work. If the work is completed after 2 more days, B alone could do the work in

how many days? Ans: 6 6. 90 men are engaged to do a piece of work in 40 days but it is found that in 25 days, work is completed. How many men should be allowed to go off so that the work may be finished in time? Ans: 15 7. 36 workmen are employed to finish a certain work in 48 days. But it is found that in 24 days only work is done. How many more men must be taken to finish the work in time? Ans: 18 8. If 12 men or 18 women can do a piece of work in 14 days. How long will 8 men and 16 women take to finish the work? Ans: 9 days 9. 20 men complete one-third of a work in 20 days. How many more men should be employed to finish the rest of work in 25 more days? Ans: 12 10. 3 men can do a piece of work in 6 days. 5 women can do the same work in 18 days. If 4 men and 10 women work together, then how long will it take to finish the work? Ans: 3 days

11. 3 men can do a piece of work in 18 days. 6 children can also do that work in 18 days. 4 men and 4 children together will finish the work in how many days? Ans: 9 12. A alone can complete a work in 12 days and B alone can complete the same work in 24 days. In how many days can A and B together complete the same work? Ans: 8 days 13. Meeshu gets Rs. 110 for every day that he works. If he earns Rs. 2750 in a month of 31 days, for how many days did he work? Ans: 25 days 14. 10 men and 8 women together can complete a work in 5 days. Work done by one woman in a day is equal to half the work done by a man in one day. How many days will it take for 4 men and 6 women to complete that work? Ans: 10 days. 15. If one man or two women or three boys can finish a work in 88 days, then how many days will one man, one women and one boy together take to finish the same work? Ans: 48 days 16. A and B can complete a work in 12 days and 18 days, respectively. A begins to do the work and they work alternately one at a time for one day each. The whole work

will be completed in how many days? Ans: 14 17. It is given that 16 men working 18 h a day can build a wall 36 m along, 4 m broad and 24 m high in 20 days. How many men will be required to build a wall 64 m long, 6m broad and 18 m high working 12 h a day in 16 days? Ans: 60 18. A contract is to be completed in 92 days and 234 men were set to work, each working 16 h a day. After 66 days, of the work is completed. How many additional men may be employed so that the work may be completed in time, each man now working 18 h a day? Ans: 162 19. 12 engines consume 30 metric tons of coal when each is running 18 h a day. How much coal will be required for 16 engines, each running 24 h a day, it being given that 6 engines of former type consume as much as 8 engines of latter type? Ans: 40 tones 20. A garrison of 6600 men had provisions for 64 days at the rate of 1700 g per head. At the end of 14 days, reinforcement arrives and it was found that the provision will last 34 days more at the rate of 1650 g per head. What is the strength of the reinforcement? Ans: 3400

21. 6 men can do a piece of work in 12 days while 8 women can do the same work in 18 days. The same work can be done by 18 children in 10 days. 4 men, 12 women and 20 children work together for 2 days. If only men have to complete remaining work in 1 day, then find the required number of men. Ans: 36 22. A certain number of persons can dig a trench 200 m long, 100 m broad and 20 m deep in 20 days. The same number of persons can dig another trench 40 m broad and 30 m deep in 60 days. Find the length of the 2nd trench Ans: 1000m 23. If a certain number of workmen can do a piece of work in 50 h, in how many hours will another set of an equal number of men, do a piece of work, twice as great, supposing that 4 men of the 1st set can do as much work in 1 h as 6 men of the 2nd set do in 1 h? Ans: 150 24. If m men working m h per day, can do m units of work in m days, then n men working n h per day would be able to complete how many units of work in n days? Ans: 25. A contractor undertook to do a certain piece of work in 18 days. He employed certain number of men but 12 of them being absent from the very 1st day, the rest could finish the work in 30 days. Find the number of men originally

employed Ans: 30 26. There is sufficient food for 800 men for 62 days. After 56 days, 560 men leave the place. For how many days will the rest of the food last for the rest of the men? Ans: 20 days 27. Rashmi can do a piece of work in 16 days. Ravina can do the same work in 12 days while Gitika can do it in 32 days. All of them started to work together but Rashmi leaves after 4 days. Ravina leaves the job 3 days before the completion of the work. How long the work last? Ans: 9 days 28. Sita can complete a work in 10 days. Geeta is 25% more efficient than Sita and Rita is 60% more efficient than Geeta. How many days will they taken to complete that work? Ans: 6 days 29. A and B can do a piece of work in 9 days 18 days, respectively. As they were III, they could do 90% and 72% of their efficiency respectively. How many days will they take to complete the work together? Ans: 2 30. A can do part of a work in 18 days. B can do part of the lane work in 12 days and C can do 60% of the lane work in 24 days. If A, B and C do the work alone for 4 days, 6 days

and 8 days, respectively. What percent of work is remaining? Ans: 30% 31. X can do 20% of a work in a day, Y can do 35% of the same work in a day and X,Y and Z together can do 50% of the same work in a day. How much percent of work can be done by Z in a day? Ans: 5% 32. A, B and C can do a piece of work in 18, 24 and 36 days, respectively. They work alternatively, first day C, Second day B and third day A, fourth day C and so on. How many days will be needed to complete the work like this way? Ans: 24 33. Eight children and 12 men complete a certain piece of work in 9 days. Each child takes twice the time taken by a man to finish the work. In how many days will 12 men finish the same work? Ans: 12 34. One man and one women can do work in 10 days. Two men can do the work in 8 days. In how many days one woman alone can do the same work? Ans: 26 35. A and B can together do a work in 24 days. B completes one-third of the work in 12 days. In how many days can A

complete the remaining work? Ans: 48 36. 12 men take 18 days to complete a work whereas 12 children take 27 days to complete the same work. How many days will 10 men and 12 children together take to complete the same work? Ans: 12 days 37. If A and B can do a piece of work in 15 days, B and C in 20 days wheras A and C can do it in 30 days, then A, B and C together can do it in how many days? Ans: 13 days 38. Two pipes A and B can fill a cistern individually in 20 minutes and 30 minutes respectively. A third waste pipe C can empty the cistern in 1 hour. If both the pipes A and B and the waste pipe C are opened simultaneously and initially the cistern is empty, then the cistern will be filled in Ans: 15 minutes 39. A 50 metre long and 35 metre wide pond was dug by 250 labourers in 18 days under the food for work programme. The number of days in which a 70 metre long and 40 metre wide pond having the same depth can be dug by 3000 labourers is Ans: 24

40. A and B can do separately a piece of work in 20 and 30 days respectively. They work together for some time and then B stops. If A completes the rest of the work in 10 days, then B has worked for Ans: 6 days 41. A takes one hour to dig a pit of metres dimension, While B takes one and a quarter hour. If workers work for 8 hours per day and 72 pits are required to be dug, then A and B together will complete the work in Ans: 5 days 42. A farmer ploughing a certain area of land at the rate of 10m2 per hour finished his work at 6 pm. If he ploughs at the rate of 12 m2 per hour, he finishes his work at 4 p.m. The total square metre of land he was ploughing was Ans: 120 m2 43. A completes of a digging work on the first day and of the remaining work on the second day. He has to dig 8 cubic metres on the third day to complete the work. The total cubic metres digging to be done was Ans: 18 cu.m 44. A tank of length, breadth and height 2m, 3.75 m and 4.73 m respectively is filled by a tap in two hours. Time needed to fill up a tank having dimensions double of the above will be Ans: 16 hours

45. X and Y together finish a work in 8 hours. If X alone can finish it in 12 hours, then Y alone can finish the same in Ans: 24 hours 46. If x men can do a piece of work in 8 days and (x+4) men could do the same work in 6 days, then x is equal to Ans: 12 47. A can do a piece of work in 24 days. If B is 60% more efficient than A, then the number of days required by B to do the same work is Ans: 15 48. If A and B can do a piece of work in 10 and 15 days respectively, then the amount of work they can together do in 3 days is Ans: 49. A man and 3 women can do a piece of work in 20 days. If a woman can do 50% of the work that a man can do, in how many days a woman will do the job when engaged alone? Ans: 100 days 50. If 5 men take 15 hours to harvest a crop, then 7 women will do the same job in how many hours, given that a man does 40% more work as compared to the work done by a woman? Ans: 15 hours

51. A and B can do a work in 2 days. If B alone can do the same work in 6 days, then A alone can do twice as great work in Ans: 6 days 52. A tap can fill a tub with water in 6 hours, and another tap attached to the tub can empty in 10 hours, then the time to fill the tub when both the taps are opened at a time is Ans: 15 hours 53. 40 men can build a wall 20 m high in 15 days. The number of men required to build a similar wall 25 m high in 6 days, will be Ans: 125 54. Pipe A can fill a tank in 4 hours and pipe B can empty it in 6 hours. If both of them are opened at the same time when the tank is empty, then number of hours required to fill the tank will be Ans: 12 55. A certain job is assigned to a group of men to do in 20 days. But 12 men did not turn up for the job and the remaining men did the job in 32 days. The original number of men in the group was Ans: 32 56. 14 persons can complete a work in 16 days. 8 persons started the work in 12 days after they started the work 8

more person joined them. How many days will they take to complete the remaining work? Ans: 8 days 57. 15 men can complete a work in 10 days while 20 boys can complete the same work in 15 days. How many days will 10 men and 10 boys together take to complete the same wok? Ans: 10 58. 14 workers can make 1400 toys in 5 days. One day after they started the work 14 more workers joined them. How many days will they take to complete the remaining work? Ans: 2 59. 14 men can complete a work in 12 days. 4 days after they started the work, 2 more men joined them. How many days will they take to complete the remaining work? Ans: 7 60. Rohan and Sunil separately can complete a work in 8 hours and 4 hours respectively. How much time will they take when working together? Ans: 2 hours 61. Ganesh, Ram and Sohan together can do a work in 16 days. If Ganesh and Ram together can do the same work in 24 days then, how long will take Sohan alone to do the same

work? Ans: 48 days 62. A and B together can do a work in 8 days. If A alone can do it in 12 days, then in how many days can B alone do it? Ans: 24 63. A and B together can do a work in 24 days. B alone does its part in 12 days. How long will A alone take to do the remaining work? Ans: 48 64. Ram, Dilip and Shekhar can Complete a work in 20 days. If Ram and Dilip together can complete the same work in 30 days, then how long will Shekar take to complete it? Ans: 60 65. A and B separately can complete a work in 6 days and 3 days respectively. If they work together, then in how many days will they complete the work? Ans: 2 66. A certain work can be done in a certain time by 25 men, with 5 men less, it could have been done in 3 days more. In what time can it be done by 40 men? Ans: 7 days

67. A certain work can be done in a certain time by 36 men, but had there been 9 men more, it could have been done in 5 days less. In how many days can 20 men do it? Ans: 45 days 68. A wall can be built by a certain number of masons in 27 days. But it requires 15 men less to finish it in 30 days. How many masons will build it in 50 days? Ans: 81 69. A and B can do a work in 12 and 20 days respectively. If, after they work at it together for some time, C who can do the whole work in 10 days, finishes it in 2 days, how long did A and B work? Ans: 6 days. 70. 90 men are engaged to do a piece of work in 40 days, but it is found that in 25 days 2/3 work in completed. How many men should be allowed to go off so that the work may be finished in time? Ans: 15 71. 8 men with 2 boys can do a piece of work in 7 days, which 25 men with 13 boys can do in 2 days. What fraction of the whole can be done in 1 day by 11 men with 20 boys? Ans: 1/3 72. One man works for 5 hours a day for 10 days and completes a piece of work. One boy works for 8 hours for 20

days to complete the same job. What is the ratio of their efficiencies? Ans: 16:5 73. A is thrice as good a worker as B & takes 8 days less to do a piece of work than B. In how many days can B do the work? Ans: 12 days 74. A and B can do a piece of work in 12 days, B and C in 15 days and C and A in 20 days. When they work together, the time required will be Ans: 10 days 75. If 60 guns firing 5 rounds in 6 min kill 350 men in 1 hours, how many guns firing 7 rounds in 9 min will kill 980 men in 25 min at the same rate? Ans: 240 guns 76. If 7 men or 8 women or 10 boys can finish a piece of work in 24 days of 9 hours, find how many men with the help of 4 women and 5 boys can finish it in 18 days of 6 hours? Ans: 7 men 77. A can eat 10 burgers in 2 days and B can eat 20 burgers in 1 day. For how long will 250 burgers last if both start eating them together? Ans: 10 days

78. If 10 men can complete a piece of work in 30 days, how many men are required to complete the same in 25 days? Ans: 12 79. 10 men can complete a piece of work in 18 days. After 6 days, 5 more men joined. In how many days the remaining work would be completed? Ans: 12 80. 15 persons can fill 35 boxes in 7 days. How many persons are required to fill 65 boxes in 5 days? Ans: 39 81. If 30 men working 7 hours a day can do a piece of work in 18 days, in how many days will 21 men working 8 hours a day do the same piece of work? Ans: 22 82. If 3 men or 4 women can plough a field in 43 days, how long will 7 men and 5 women take to plough it? Ans: 12 days 83. A and B can together finish a work in 20 days. They worked at it for 20 days and then B left. The remaining work done by A alone in 20 more days. A alone can finish the work in Ans: 60 days

84. A does half as such work as B in three-fourth of the time. If together they take 18 days to complete the work, how much time shall B taken to do it? Ans: 30 days 85. A can do a certain job is 12 days. B is 60% more efficient than A. The number of days, it takes B to do the same piece of work is Ans: 7 86. If Ramesh, Suresh and Harish can do a piece of work in 15 days, 10 days and 6 days respectively, how long will they take to do it, if all the three together complete the remaining work? Ans: 3 days 87. Twelve men can complete a work in 8 days. Three days after they started the work and 3 more men joined. In how many days will all of them together complete the remaining work? Ans: 4 88. A and B can separately to do a piece of work in 20 days and 15 days respectively. They worked together for 6 days, after which B was replaced by C. If the work was finished in next 4 days, then the number of days in which C alone could do the work will be Ans: 40

89. A does half as much as B and C does half as much work as A and B together. If C alone can finish the work in 40 days, then together all will finish the work in Ans: 13 days 90. A, B and C can do a piece of work in 36, 54 and 72 days respectively. They started the work but A left 8 days before the completion of the work while B left 12 days before the completion. The number of days for which C worked is Ans: 24