Two workers

Two workers work together and perform the job in 12 hours. If one has done half the work and then the second worker next half of the work it will take 25 hours. How long would it take job them separately?

Correct answer:

a =  20 h
b =  30 h

Step-by-step explanation:

$$\begin{gathered} {\displaystyle \frac{1}{a}}+{\displaystyle \frac{1}{b}}={\displaystyle \frac{1}{12}} \\ {\displaystyle \frac{x}{a}}={\displaystyle \frac{1}{2}} \\ {\displaystyle \frac{y}{b}}={\displaystyle \frac{1}{2}} \\ x+y=25 \\ a=20 \\ b=30 \\ x=10 \\ y=15 \end{gathered}$$

Try another example

Related math problems and questions:

• Workers
  Two workers A and B, will be done work together for 15 days. They worked together for 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?
• Workers
  Two workers fulfill a certain task when working together for 5 days, the first if he worked himself done work in 13 days. How many days will do whole job a second worker?
• Turners
  Two turners perform joint work in 3 hours. The first turner would perform the job himself in 7 hours. How long would the same job last for a second turner if he worked alone?
• Two workers
  One worker needs 40 hours to do a job, and the second would do it in 30 hours. They worked together for several hours, then the second was recalled, and the first completed the job itself in 5 hours. How many hours did they work together, and how much did
• Three workers
  Three workers A, B, C have to work on a specific task. Workers A and B completed whole task in 14 days, B together with C for 23 days, A together with C for 13 days. How long it would take to complete the task every one of them alone? How long it would ta
• Tractors
  Two tractors plow the field in 4 hours together. If the first tractor plow half of the field and then the second tractor completed the job, it would take 9 hours. How many hours does the field plow for each tractor separately?
• Harvesters
  The first harvester will harvest the grain from the field in 20 hours, the second, the more powerful in 10 hours. How long will it take to harvest this field by both harvesters if the second harvester has to be set up first and this takes 2 hours? The fir
• 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 the time that Dorota would do the work herself and the time that Michal would do it himself.
• Two workers
  Two workers together execute some work in 10 days. The first worker would have done himself in 20 days. How many days would have done himself a second worker?
• Weighted harmonic average
  Ten workers will do some work in 2 minutes, five workers in 10 minutes and three workers in 6 minutes. How many minutes per average worker per worker?
• Work together
  Two bricklayers plastering a wall. The first would plaster it in 8 hours, the second in 12 hours. How many hours will they be done with the work if they work together?
• Work
  The first worker would need less than 4 hours to complete the task than the other worker. In fact, both workers worked for two hours together, then the first worker did the remaining work himself. In what proportion should the remuneration of the workers
• Together 3
  If Sally can paint a house in 4 hours, and John can paint the same house in 6 hours, how long will it take for both of them to paint the house together?
• Two pumps
  The first pump fills the tank in 24 hours second pump in another 40 hours. For how long will it take to fill the tank if it operates both pumps at the same time?
• Mow the lawn
  Dano would mow the lawn in 12 hours and Milada in 16 hours. How long will take the lawn mow together?
• Workers
  Four workers plan to work on the gym floor for six hours. After an hour of working together, one of the workers went to the doctor. How long will it take the remaining three workers to finish the job?
• Parquet floor
  Three workers laid parquet floor for 2.301 hour. The first one would do this work alone 7 hours, the second in 6 hours. For how many hours would fulfill this work the third worker, if he worked alone?