Time and Work Problems Shortcuts and Tricks


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Video duration: 15:28
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Solved examples on Time and Work dealing with ideas of proportionality, efficiency, pipes & cisterns, etc.

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  1. Three pipes A, B and C can fill a tank in 6 hours. After
    working it together for 2 hours, C is closed and A and B can
    fill the remaining part in 7 hours. The number of hours taken
    by C alone to fill the tank is

  2. A, B and C together can do a piece of work in 40 days. After
    working with B and C for 16 days, A leaves and then B and
    C complete the remaining work in 40 days more. A alone
    could do the work in

  3. 2. A work can be completed by 40 workers in 40 days. If 5 workers leave every 10 days, how many days work will be completed.


    Formula : A = 100 % / 40 days = 25 % every 10 days by 40 workers

    10 days = 25 % by 40 workers
    10 days = 21.87 % by 35 workers
    10 days = 18.75% by 30 workers
    10 days = 15.62 % by 25 workers
    10 days = 12.5% by 20 workers
    93.74 %

    100 % / 93.74% = 1.066 40 days + 10.66 = 50.66 Days

  4. Please provide the solution of this question–

    In village A, 12 men and 18 boys completed construction of a health center in 60 days, by working for 7.5 hours a day. Subsequently the residents of the neighbouring village B also decided to construct a health centre in their locality, which would be twice the size of the facility built in village A. If a man is able to perform the work equal to the same done by 2 boys, then how many boys will be required to help 21 men to complete the work in village B in 50 days, working 9 hours a day?

    (1) 45 boys

    (2) 48 boys

    (3) 40 boys

    (4) 42 boys

    (5) None of these/Cannot be determined

  5. Q. A and B can independently finish a piece of work in 25 and 20 days. They started working together after few days A left . after that B could finish the remaining work in 11 days. After how many days A left the work.
    kindly tell me solution to this question

  6. Q. A and B completed a work together in 5 days. Had A worked at twice the speed and B at half the speed, it would have taken them four days to complete the job. How much time would it take for A alone to do the work?

  7. Some persons were assigned a work to do in 26 days .They started the work
    but after 6 days, four persons were absent and remaining work was
    completed in 24 days. How many persons were assigned in beginning?
    1. 24
    2. 20
    3. 26
    4. 30
    6. Cannot be determined

  8. Hi.gautam..i think and is 8.bcz B can do 1unit work so in remaining 3 days B can only 3 unit work so.18-3=15unit work can done by A+B.Bt in A+B do the work 3unit per day so A+B done the work together in 5 days.So Total days=5+3=8.

  9. sir can you make a playlist ??? please coz it is very difficult to watch the video in order as you said at the beginning  to watch the video on basic concept of time and work but i am unable to find that so if they are in order it will be quite helpful…thankyou  and at last i would like to thanxx for above awesome video…

  10. Q4 it should be 12 days….they both start working together and can complete the work in 6 days. so in first 3 days they complete 1/2 of the work and then A leaves..so B will have to complete rest 1/2 of the work in 9 days so in total it takes 12 = (3 +9) days to complete.

  11. Sir i m learning the basics of mathematics now..please tell me how to solve with step by step example of 0.75/25*100
    i know the answer  is 0.03
    But please help me how to solve it without calculator..
    Thank you

  12. thanku for easy explanation sir. Can u pls solve this prob, " Twenty-four men can complete a work in sixteen days. Thirty-two women can complete the same work in twenty-four days. Sixteen men and sixteen women started working and working for twelve days. How many more men are to be added to complete the remaining work in 2 day?"

  13. Hello ,

    I have one doubt in question 6 :
    Let the total work to be done is 630( LCM of A,B,C):
    the unit of work done by A in 1 min : 630/35 : 18 
    The unit of work done by B i :                        14
    The unit of work done by C                            21

    For 7 mins the work done will be 7*(18+14)/630 = 224/630

    The amount of work left is 1-224/630 = 406/630
    now the total time taken will be = (18+14-21)t/630=406/630
    t= 37 days approx
    can you please tell me where my logic is wrong


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