Harmonic mean + work - practice problems - page 4 of 6
Number of problems found: 109
- 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? - Reading records
Lucy, Tereza, and Petra decided to compile the compulsory reading records together. It would take 30 days for Lucia alone, 36 for Tereza, and 45 for Petra. How long will it take to make records if they will work together? - Half-filled 7336
The water tank is filled with the first inflow in one hour and 10 minutes and the second in 60 minutes. How many minutes will the tank be half-filled with both inlets if the second outlet is opened 12 minutes later? - Work together
Michal and Dorota would do the work together in 2.25 hours. If Dorota had to do it herself, it would have taken her 6 hours longer than Michal. Determine when Dorota would do the work herself and that Michal would do it himself. - Cleaners
Milan would clean up the room for 2.5 hours, and Eric would take 10 hours. How long do they sweep the room together? - Independently 12921
Factory A can fulfill the order independently in 10 days. Factory B fulfills the same order in 16 days. How many days will the order be completed if only plant B works on it for 3 days and then both plants together? - Painters
The first team of painters would paint the bridge in 15 days, the second in 10 days. After three days of working together, the second team goes out and continues only with the first team. How many days took the second team to finish painting the bridge? - Painters
The first painter painted the fence himself for 4 hours, the second painter 1.2 hours sooner than the first, and the third painter slowest up to 16 hours. How long took them to paint the fence if they worked together? - Tractors
Fields go plow two tractors with various performances. The first tractor plows the whole field in 11 hours. The second tractor plows the whole field 19 hours longer. How long does it take to plow the whole field with two tractors? - 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? - Kilometers 7684
My father went to dig 6 kilometers of beet at 6:00 pm. It would take him 12 hours. After an hour, the son arrived, and they finished digging at 10:00. How long would it take to dig 6 km of beet for his son? - Minute average
In a factory, four workers are assigned to complete an order received for dispatching 1400 boxes of a particular commodity. Worker A takes 4 minutes per box, Worker B takes 6 minutes per box, C takes 10 minutes per box, and D takes 15 minutes per box. Fin - In and out
The empty tank is filled in 12 minutes and empty in 16 minutes. How long does it take to fill if we forget to close the drain? The tank has 1000 liters of volume. - Parquet floor
Three workers laid the parquet floor for 2.301 hour. The first would do this work alone 7 hours, the second in 6 hours. For how many hours would fulfill this work for the third worker if he worked alone? - Simultaneously 17821
The reservoir is filled with the first pump in 30 hours, the second in 24 hours, and the third in 20 hours. How long does it take to fill the reservoir if all pumps are switched on simultaneously? - Calculation 7334
In a computer center, one computer would work 12 hours to solve a task, and another, more powerful, would solve the same task for 10.5 hours. If both computers work together, the calculation time would be reduced for a certain period. Calculate how long i - Three pumps
We are filling the pool. The pool would fill the first pump in 12 hours and the second in 15 hours. If all three pumps ran simultaneously, they would fill the pool for 4 hours. How long would the pool fill only with the third pump? - Three workers
Three workers, A, B, and C, have to work on a specific task. Workers A and B completed the task in 12 days, B with C for 19 days, and A with C for 24 days. How long would it take to complete the task for everyone alone? How long would it take to complete - Construction 7709
Two construction companies are working on the landscaping. The first would do the whole job in 12 days, the second in 20 days. How long will they work together if the first start working when the second has already worked 4 days? - Boots
Master shoemaker has three apprentices. First, do one pair of boots for two days, second for one day, and third for 1.5 days. How long would it take to make a couple of boots if they worked together?
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