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,
It takes 5 people about 18 days to construct a room. If we employ 15 people, then how may days will they take to construct the room? | |||
| Right Option : A | |||
| View Explanation | |||
Students / Parents Reviews [20]
Abhyas academy is great place to learn. I have learnt a lot here they have finished my fear of not answering.It has created a habit of self studying in me.The teachers here are very supportive and helpful. Earlier my maths and science was good but now it has been much better than before.
Barkha Arora
10thUsually we see institutes offering objective based learning which usually causes a lag behind in subjective examinations which is the pattern followed by schools. I think it is really a work of planning to make us students grab the advantages of modes of examination, Objective Subjective and Onli...
Anika Saxena
8thMy experience with Abhyas academy is very nice or it can be said wonderful. I have been studying here from seven class. I have been completing my journey of three years. I am tinking that I should join Abhyas Academy in tenth class as I am seeing much improvement in Maths and English
Hridey Preet
9thAbhyas 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
10thIn terms of methodology I want to say that institute provides expert guidence and results oriented monitering supplements by requsite study material along with regular tests which help the students to improve their education skills.The techniques of providing education helps the students to asses...
Aman Kumar Shrivastava
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.
Cheshta
10thAbhyas institute is one of the best coaching institute in the vicinity of Ambala cantt.The institute provides good and quality education to the students.The teachers are well experienced and are very helpful in solving the problems. The major advantages of the institute is extra classes for weak...
Shreya Shrivastava
8thAbout Abhyas metholodology the teachers are very nice and hardworking toward students.The Centre Head Mrs Anu Sethi is also a brilliant teacher.Abhyas has taught me how to overcome problems and has always taken my doubts and suppoeted me.
Shreya Shrivastava
8thMy 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
8thI have spent a wonderful time in Abhyas academy. It has made my reasoning more apt, English more stronger and Maths an interesting subject for me. It has given me a habbit of self studying
Yatharthi Sharma
10thA 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
7thAbhyas is good institution and a innovative institute also. It is a good platform of beginners.Due to Abhyas,he has got knoweledge about reasoning and confidence.My son has improved his vocabulary because of Abhyas.Teacher have very friendly atmosphere also.
Manish Kumar
10thWe started with lot of hope that Abhyas will help in better understnding of complex topics of highers classes. we are not disappointed with the progress our child has made after attending Abhyas. Though need to mention that we expected a lot more. On a scale of 1-10, we would give may be 7.
Manya
8thMy experience with Abhyas Academy has been very good. When I was not in Abhyas whenever teacher ask questions I could not speak it confidently but when I came in Abhyas, my speaking skills developed and now I am the first one to give the answer of teachers question.
Upmanyu Sharma
7thIt 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
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
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
7thIt 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
8thAbhyas institute is one of the best coaching institute in the vicinity of Ambala Cantt area. The teachers of the institute are well experienced and very helpful in solving the problems of the students.The good thing of the institute is that it is providing extra classes for the students who are w...
