# Painters

First painter painted fence himself for 12 hours, the second painter 3 hours sooner than first, and the third painters slowest up to 20 hours.

How long took them paint fence if worked together?

Result

x =  4.09 h

#### Solution:

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

Be the first to comment!

#### To solve this example are needed these knowledge from mathematics:

Looking for a statistical calculator? Looking for help with calculating harmonic mean?

## Next similar examples:

1. Painters
The first team of painters would paint bridge in 15 days, the second in 10 days. After 3 days of working together second team goes out and continue only first team. How many days took second team to finish painting the bridge?
2. Painters 4
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?
3. Parquet floor
Three workers laid parquet floor for 1.957 hour. The first one would do this work alone 5 hours, the second in 9 hours. For how many hours would fulfill this work the third worker, if he worked alone?
4. Trucks
Truck take you the some amount of clay in 30 hours. Second truck in 40 hours. Trucks carted the clay away some time together then the second truck broke down and the first one completed the job in five hours. What time worked together?
5. Tributaries
The first tributary fill pool with water in 15 hours. The second tributary fill pool in 10 hours. For how many hours the pool is filled with both tributaries?
6. Two valves
Water fill the pool by two valves for 16 days. After 6 days the first valve was stopped and the second valve fill pool for 12 days. How many days took to fill the pool each of the valves individually?
7. Apprentice
Worker and apprentice execute the work for 6 hours. Worker performs himself in 10 hours. How long do the work of an apprentice?
8. Two diggers
There are two diggers. One digger digs a pit 83 hours second gidding 1.4 times faster. a) how long took to dig a pit second digger b) how long took dig together
9. Blueberries
Marie earns 1.8 liters of blueberries for 1.2 hours, Peter 2.6 liters for 1.2 hours. How long have earns together one liter?
10. Pumping
The tank is filled with a larger pump in 12 hours and with scond pump in 15 hours. For how long does the tank fill when both pumps are switched on at the same time?
11. Workers
Group of workers washing half of the windows of the building in two hours. How long will take half the workers wash all the windows of the building?
12. 5 pumps
Five pump to pump 3 hours 1600 hl of water. How long pumped same amount of water 4 pumps?
13. 4 pipes
The tank flows out by 4 pipes in 6 hours 120 hl water. How much water flows out of 5 pipes of the same diameter in 14 hours?
14. Digging 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?
15. Inflow - outflow
The tank will fill by inflow for 93 minutes and empties by outflow for 104 minutes. How long take to fill tank if it is also opened the inflow and outflow?
16. Pond
A pond with two open floodgates will emptied in 20 days. A larger floodgate will emptied whole pond in 30 days. For how long would he be emptied with a smaller floodgate.
17. Tonic
One package tonic consume Mom 12 weeks and daughter for 14 weeks. 4 weeks they use the same cream together and then only daughter. How many weeks endured tonic to daughter then?