Time and Work
Time and Work
As we all know that the amount of work done by a person varies directly with the time taken by him (her) to complete it .Thus, if a man can complete a piece of work in 10 days, then by unitary method,we can say that in one day he will do only th part of the total work. On the other hand ,if a man completes
th of the work in one day , he will take 10 days to complete the work .Thus, we obtain the following rules:
Illustration: Together, Chandu and Monu plough a field in 4 days . Monu alone takes 6 days to plough the same field .In how many days can Chandu alone plough the field ?
Solution: We have, time taken by Chandu and Monu plough the field together = 4 days.
Time taken by Monu to plough the field = 6 days. Chandu and Monu 1 day work =
Monu 1 day work = . Now, Chandu 1 day works = (Chandu and Monu 1 days work ) - (Monu 1 days work )
Hence, Chandu can plough the field in 12 days.
Illustration: A and B can do a piece of work in 12 days; B and C in 15 days; C and A in 20 days. In how many days will they finish it together and separately?
Solution: We have, A and B can do a piece of work in 12 days; B and C in 15 days; C and A in 20 days
So, A and B's 1 day's work = ..............................(1)
B and C's 1 day's work = ..............................(2)
C and A's 1 day's work = ..............................(3)
Adding equations (1), (2), (3) we have
2(A + B + C)'s 1 day's work =
Hence, (A + B + C)'s 1 day's work
(A + B + C)'s 1 day's work =
Hence, A, B and C together can finish the work in 10 days.
Now,
A's 1 day's work = (A, B,and C's 1 day's work ) - (B and C's 1 day's work)
So, A alone can finish the work in 30 days.
Now,
B's 1 day's work = (A, B,and C's 1 day's work ) - (A and C's 1 day's work)
So, B alone can finish the work in 20 days.
Now,
18 men can do a piece of work in 20 days. In how many days can 30 men finish the same work ? | |||
| Right Option : D | |||
| View Explanation | |||
6 men can complete the electric fitting in a building in 7 days. How many days are required if 21 men do the job? | |||
| Right Option : C | |||
| View Explanation | |||
A and B can do a piece of work in 10 days, B and C in 15 days,C and A in 20 days. How many days will be taken by A,B,and C working together to finish the work? | |||
| Right Option : B | |||
| View Explanation | |||
Students / Parents Reviews [10]
Abhyas is a complete education Institute. Here extreme care is taken by teacher with the help of regular exam. Extra classes also conducted by the institute, if the student is weak.
Om Umang
10thIt was good as the experience because as we had come here we had been improved in a such envirnment created here.Extra is taught which is beneficial for future.
Eshan Arora
8thBeing a parent, I saw my daughter improvement in her studies by seeing a good result in all day to day compititive exam TMO, NSO, IEO etc and as well as studies. I have got a fruitful result from my daughter.
Prisha Gupta
8thMy experience with Abhyas is very good. I have learnt many things here like vedic maths and reasoning also. Teachers here first take our doubts and then there are assignments to verify our weak points.
Shivam Rana
7thAbhyas Methodology is very good. It is based on according to student and each child manages accordingly to its properly. Methodology has improved the abilities of students to shine them in future.
Manish Kumar
10thMy experience was very good with Abhyas academy. I am studying here from 6th class and I am satisfied by its results in my life. I improved a lot here ahead of school syllabus.
Ayan Ghosh
8thA marvelous experience with Abhyas. I am glad to share that my ward has achieved more than enough at the Ambala ABHYAS centre. Years have passed on and more and more he has gained. May the centre flourish and develop day by day by the grace of God.
Archit Segal
7thMy experience with Abhyas academy is very good. I did not think that my every subject coming here will be so strong. The main thing is that the online tests had made me learn here more things.
Hiya Gupta
8thIt has a great methodology. Students here can get analysis to their test quickly.We can learn easily through PPTs and the testing methods are good. We know that where we have to practice
Barkha Arora
10thIt was a good experience with Abhyas Academy. I even faced problems in starting but slowly and steadily overcomed. Especially reasoning classes helped me a lot.
