Work + harmonic mean - practice problems
Number of problems found: 110
- Together 83245
Jarka and Jana decided to decorate their common room. If Jarka painted it alone, it would take her 4 hours, and Jane 3 hours. How long would they paint the room if they painted together? - Corrects 83017
The new teacher corrects papers for 9 hours, and the older one fixes them in 6 hours. How much will they repair together? - Together 82965
An older digger would dig a ditch by himself in 6 hours. A younger digger can handle the same trench in 3 hours. How long would it take them to dig if they worked together? - Companies 82884
The K+S company will mow the meadow in ten hours. The Kosačka company mows the meadow in six hours. How many hours would these companies mow one such meadow if they worked together? - Simultaneously 82806
An empty tank is filled with inflow in 30 minutes. A full tank is emptied in 75 minutes with an open drain. How long does it take for an empty tank to fill up if both the inlet and outlet are open simultaneously? - Excavators 82208
Two excavators dig a pit in 12 days. How much shorter will this job take if 8 excavators dig the hole? In 3 or 9 days? - Distribute 82137
We have a profit of 40000e, and the work took 30 days. The first worker is promised 38% of the profit but only works for 15 days, the second worker is promised 33% of the profit and works for 20 days, and the third is promised 28% of the profit and works - Together 82027
Eva sews a costume in 6 hours, Ivana in 8 hours, and Monika in 4 hours. How long will it take them to make the costume if they work together? - Basement 81681
After the flood, the Nováks would pump water out of the basement with one pump in 120 minutes, the second in 300 minutes, and the third in 600 minutes. How many minutes will it take them to pump the water out of the basement if they use all the pumps at o - Apartment 81654
A woman cleans an apartment in 8 hours and a man in 10 hours. How many hours will they clean together? - Simultaneously 81441
The tank is filled through three openings, A, B, and C. The simultaneously open inlets A and B are filled in 1 hour, inlets A and C in 45 minutes, and inlets B and C in 1.5 hours. How long would it take to fill each inlet separately? - Together 81046
Two painters are painting the factory fence together. If everyone worked alone, the first would finish the job in 16 days, the second in 20 days. When will they finish the work together? - Two painters
Two painters are assigned to finish painting the houses in a housing project. John can finish a house in 4 days. Kurt painted it in 3 days. How long would it have taken if John and Kurt worked painting the house together? - Construction 71794
Two different trucks together would bring the construction material in 6 hours. However, after 4 hours, the first car was transferred to another job, and the second one was driven for another 6 hours. How many hours would it take for the first car to deli - Apartment 71114
A father and son paint the apartment together in 6 hours. My father would paint the apartment in 9 hours. In how many hours would the son paint the apartment himself? - Restaurant 65394
The restaurant was fully booked at lunchtime. While only three waiters staffed the restaurant, guests waited an average of 45 minutes for the lunch menu. On average, how many minutes will the guests wait if the three waiters are joined by two more waiters - Together 65074
Jana washes 20 windows alone in 4 hours. Petra would be able to do it in 6 hours. How long will it take to work together? - Blueberries 48771
Mirka picks up a bucket of blueberries in two hours. Lojzo fills one-third of the bucket every hour. How long would it take to fill one bucket together to the brim? - Assemblers 47483
Two assemblers with the same daily output were to complete the assembly in 12 days. After 4 days, one of them got sick, and the other finished the assembly in another 16 days. How long would it take everyone to do the assembly by themselves? - Treatment 46571
They have 3 sprayers for the chemical treatment of the vines. The first would spray the vineyard in 12 hours, the second in 15 hours, and the third in 10 hours. How long would it take to spray the vineyard with all the sprayers combined?
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