Workers

Workers A and B will done work together for 15 days. They worked together 13.5 days. Then A worker became ill and worker B finish the job alone for 7.5 days.

If every worker was working alone, how many days took whole work for worker A and B?

Correct result:

A =  18.8 d
B =  75 d

Solution:

A=1/(1/151/(7.5/(113.5/15)))=754=18.8 dA=1/(1/15-1/(7.5/(1-13.5/15)))=\dfrac{ 75 }{ 4 }=18.8 \ \text{d}
1A+1B=115  r=113.5/15=0.1 r....7.5 1....B  B=7.5/r=75 d  1A+1B=115 1A=1151B A=11151B=18.75 \dfrac{1}{A}+\dfrac{1}{B} = \dfrac{1}{ 15 } \ \\ \ \\ r = 1 - 13.5/15 = 0.1 \ \\ r .... 7.5 \ \\ 1 .... B \ \\ \ \\ B = 7.5 / r = 75 \ \text{d} \ \\ \ \\ \dfrac{1}{A}+\dfrac{1}{B} = \dfrac{1}{ 15 } \ \\ \dfrac{1}{A} = \dfrac{1}{ 15 } - \dfrac{1}{B} \ \\ A = \dfrac{1}{ \dfrac{1}{ 15 } - \dfrac{1}{B}}= 18.75 \ \\



Our examples were largely sent or created by pupils and students themselves. Therefore, we would be pleased if you could send us any errors you found, spelling mistakes, or rephasing the example. Thank you!


Leave us a comment of this math problem and its solution (i.e. if it is still somewhat unclear...):

Showing 0 comments:
1st comment
Be the first to comment!
avatar




Tips to related online calculators
Looking for calculator of harmonic mean?
Looking for a statistical calculator?
Do you have a linear equation or system of equations and looking for its solution? Or do you have quadratic equation?
Do you want to convert time units like minutes to seconds?

Next similar math problems:

  • Six workers
    workers Six workers planned to repair the roof in 5 days. After two days, two workers get sick. How long will the remaining workers complete the roof at the same rate of work?
  • Panel house
    workers The construction company has two groups of workers. Group A has more members than B. Panel house was insulated by group A in 10 days. The same block of flats was insulated together in 6 days. How many days would group B block insulate?
  • Four painters
    painter The company sent four painters to paint the school. They should be done in 12 days. After three days, one painter got ill. How long will the remaining painters paint the school?
  • Painters 4
    painter_3 One painter will do the job for 12 days. After a 4 1/3 day he comes second to help him and complete work together for 8 days. How long would work the second painter himself?
  • Seven
    trpaslíky Seven dwarfs will cut 420 stumps in 15 hours. After five hours, the two dwarves disappear discreetly. How many hours will the remaining dwarves complete the task?
  • Bricklayers
    murar The first bricklayer would build a wall in 3 days, the second in 4 days. The first bricklayer worked alone for a day, then the second bricklayer came to his aid and they finished the work together. How long did it take to build the wall?
  • Digging companies
    companies Company A would dig a pit for 12 days, company B for 15 days, company C for 20 days and the company D for 24 days. Work began together companies C and D, but after three days joined them other two companies. How long took to dig a pit?
  • Two pumps
    pumps_4 Pump A takes twice as long to fill a tank than B . Together they take 2 hours to fill the tank. How long does each one take to fill the tank by itself?
  • Three people
    clocks_16 Three people start doing a work at a same time. The first worked only 2 hours. The second ended 3 hours before the end. On an individual basis, it would take the first time to do the work 10 hours, second 12 hours and 15 hours third. How many hours did it
  • Father and daughter
    time_14 When I was 11 my father was 35 year old. Now, father has three times older then me. How old is she?
  • ATC camp
    camp The owner of the campsite offers 79 places in 22 cabins. How many of them are triple and quadruple?
  • Hotel rooms
    hotel_3 In the 45 rooms, there were 169 guests, some rooms were three-bedrooms and some five-bedrooms. How many rooms were?
  • Father and son
    Rodina-01_1 When I was 11, my father was 35 years old. Today, my father has three times more years than me. How old is she?
  • Simply equation
    img_reci Solve this equation for x: ?
  • Dining room
    table The dining room has 11 tables (six and eight seats). In total there are 78 seats in the dining room. How many are six-and eight-seat tables?
  • Journey to school
    steps_3 On the way to school I went steady step. In the first half of the journey, I counted every second step, in the second half every third. How many steps I do when I went to school if I counted double step are 250 more than three steps?
  • Theatro
    divadlo_1 Theatrical performance was attended by 480 spectators. Women were in the audience 40 more than men and children 60 less than half of adult spectators. How many men, women and children attended a theater performance?