# 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?

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

**Showing 0 comments:**

**Be the first to comment!**

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

## Next similar examples:

- Three people

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. - Three painters

One painter would have painted the fence for 15 hours, the second in 12 hours. The plot had to be painted in four hours, so they called the third one, and all worked together. For what time would the third painter paint fence the fence alone? - Novak

Novak needed to dig up three of the same pit in the garden. The first pit dug father alone for 15 hours. His second dig son helped him and it did that in six hours. The third pit dug son himself. How long it took him? - Ball game

Richard, Denis and Denise together scored 932 goals. Denis scored 4 goals over Denise but Denis scored 24 goals less than Richard. Determine the number of goals for each player. - Family

Family has 4 children. Ondra is 3 years older than Matthew and Karlos 5 years older than the youngest Jane. We know that they are together 30 years and 3 years ago they were together 19 years. Determine how old the children are. - Hectoliters of water

The pool has a total of 126 hectoliters of water. The first pump draws 2.1 liters of water per second. A second pump pumps 3.5 liters of water per second. How long will it take both pumps to drain four-fifths of the water at the same time? - Three workshops

There are 2743 people working in three workshops. In the second workshop works 140 people more than in the first and in third works 4.2 times more than the second one. How many people work in each workshop? - Theorem prove

We want to prove the sentense: If the natural number n is divisible by six, then n is divisible by three. From what assumption we started? - Pooja

Pooja and Deepa age is 4:5, 4 years back it was 8:11. What is the age of Pooja now? - Men, women and children

On the trip went men, women and children in the ratio 2:3:5 by bus. Children pay 60 crowns and adults 150. How many women were on the bus when a bus was paid 4,200 crowns? - Legs

Cancer has 5 pairs of legs. The insect has 6 legs. 60 animals have a total of 500 legs. How much more are cancers than insects? - Elimination method

Solve system of linear equations by elimination method: 5/2x + 3/5y= 4/15 1/2x + 2/5y= 2/15 - Three unknowns

Solve the system of linear equations with three unknowns: A + B + C = 14 B - A - C = 4 2A - B + C = 0 - Linsys2

Solve two equations with two unknowns: 400x+120y=147.2 350x+200y=144 - Lee is

Lee is 8 years more than twice Park's age, 4 years ago, Lee was three times as old. How old was Lee 4 years ago? - Children

The group has 42 children. There are 4 more boys than girls. How many boys and girls are in the group? - Father 7

Father is 6 times older than his son. After 4 years, the father will only be 4 times older. What are their present ages?