Time + ratio - examples
- The work
The work was to be done by 150 workers. At the beginning of their work, their number reduced by 40, which increased the time of work by 5 and 1/3 of the schedule. How long did work take?
- Ten cashiers
Ten cashiers are open at Tesco. Customers wait an average of 15 minutes. How many other cashiers have to open to reduce the waiting time by 4 minutes?
- Five mechanics
Five mechanics will make a car for some time. How many cars can 30 mechanics produce at the same time?
- Forestry workers
In the forest is employed 56 laborers planting trees in nurseries. For 8 hour work day would end job in 37 days. After 16 days, 9 laborers go forth? How many days is needed to complete planting trees in nurseries by others, if they will work 10 hours a da
Route is long 147 km and the first day first regiment went at an average speed 12 km/h and journey back 21 km/h. The second day went second regiment same route at an average speed 22 km/h there and back. Which regiment will take route longer?
- Motion problem
From Levíc to Košíc go car at speed 81 km/h. From Košíc to Levíc go another car at speed 69 km/h. How many minutes before the meeting will be cars 27 km away?
Mr. Billy calculated that excavation for a water connection dig for 12 days. His friend would take 10 days. Billy 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?
A cyclist passes 88 km in 4 hours. How many kilometers he pass in 8 hours?
If you go at speed 3.7 km/h, you come to the station 42 minutes after leaving train. If you go by bike to the station at speed 27 km/h, you come to the station 56 minutes before its departure. How far is the train station?
Calculate how many average minutes a year is the web server is unavailable, the availability is 99.99%.
- Gimli Glider
Aircraft Boeing 767 lose both engines at 42000 feet. The plane captain maintain optimum gliding conditions. Every minute, lose 1910 feet and maintain constant speed 211 knots. Calculate how long takes to plane from engines failure to hit ground. Calculate
Calculate fixed annual personnel costs of operating monorail line 118 km long if every 5 km is station, which serve three people - one dispatcher and two switchman in 4-shift operation. Consider the average salary of the employee 885 €.
- Road repair
Road repair took 10 days for 36 workers if they worked 9 hours a day. How many days take repair same road 37 workers if they work 8 per day?
Pediatrician this month of 21 working days takes 3 days holidays. What is the probability that on Monday will be at work?
Two workers would make installation of greenhouses for 54 hours. For how many hours does the installation 9 workers?
- Daily average
Calculate the average temperature during the day, when 13 hours was 22 °C and 11 hours was 17 °C.
- TV fail
The TV has after 10,000 hours average 25 failures. Determine the probability of TV failure after 200 hours of operation.
- Salary raise
Monthly salary was 2390 Eur. During the year it was raised to 2617 Eur. Calculate the month from salary was increased that employee earned 29361 Eur during whole year.
At 8:40 the ship set sail at 12 km/h. At 19:10 followed by at 29 km/h sail boat. When sail boat catches up the ship? How many minutes will catch up took?
Car is going 95 km per hour. How long distance goes in 1 minute?