Time + system of equations - examples
Mr. Radoslav calculated that excavation for a water connection dig for 10 days. His friend would take 7 days. Radoslav worked 3 days alone. Then his friend came to help and started on the other end. On what day since the beginning of excavation they met?
- Forestry workers
In the forest is employed 63 laborers planting trees in nurseries. For 11 hour work day would end job in 43 days. After 14 days, 22 laborers go forth. How many days is needed to complete a planting trees in nurseries by others, if they will work 15 hours
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.
The boys from scout group traveled 3 days distance 105 km. Every day walked 1.3 km less than the previous day. How many kilometers scouts walked in the first day?
Workers A and B will done work together for 20 days. They worked together 18 days. Then A worker became ill and worker B finish the job alone for 11 days. If every worker was working alone, how many days took whole work for worker A and B?
A team of colleagues done the work in 20 days. After adding 2 colleagues from the beginning the work was completed in 15 days. How many members has the colleague team?
If water flows into the pool by two inlets, fill the whole for 9 hours. First inlet filled pool 8 hour longer than second. How long pool is filled with two inlets separately?
- Father and son
Father is three times older than his son. 12 years ago father was nine times older than the son. How old are father and son?
Cyclist started out of town at 20 km/h. After 0.6 hours car started behind him in the same direction and caught up with him for 52 minutes. How fast and how long went car from the city to caught cyclist?
Cyclist started at 5:00 from point N to point O. After 20 minutes, followed him at the same speed the second cyclist. Walker, which went from O to N, started at 5:40. After 56 minutes he met the first cyclist and after next 16 minutes the second cyclist. D
- Water reservoir
The water reservoir is filled through one inlet 4 hours later than both together, then another inlet 9 hours later than both together. For how long is filled by each separately?
From the cottage started first group of tourists at 10:00 AM at speed 4 km/h. The second started after them 39 minutes later at speed 6 km/h. How long and how many kilometers from the cottage will catch the first group?
First paver pave pavement for 33 hours. Second for 24 hours. Started first paver and after 5 hours, join the second. How long will they finish pavement?
- Mother and daughter
Three years ago mother was three times older than daughter. After nine years she will be only twice old. How old is mother (and daughter)?
Parents piggybacking children on vacation to its grandmother and grandfather at a city distant 150 kilometers. They agreed to meet halfway. Parents will be travel at 90 km/h, grandmother and grandfather at 60 km/h. Parents depart at 12:00 hours. When grand
- Grandson and granddad
Grandson with grandpa they counted how many years have together. Their product is 365. How many years is the sum of their years.
- The professor's birthday
Professor of mathematics had 36 birthdays. The director congratulated him. The professor asked the director: "And how old are you?" The director replied: "I'm exactly twice as many years than you were when I was old as to you today." How old is the direc
- Age ratios
The ratio of the age of the mother and daughter is 5:2 and after seven years the ratio will be 2:1.Before how many years was born the daughter?
Ten workers must pave road street for 22 working days. After four days were for speeding up work added two more workers. a) After how many work days now workers completes the paved road? b) How many working days it took a total paved road?
- Three siblings
Three siblings have birthday in one day-today. Together they have 35 years today. The youngest is three years younger than middle and the oldest is 5 years older than middle. How old is each?