Ratio - problems

On solving problems and tasks with proportionally we recommend hint rule of three. Rule of three (proportionality) help solve examples of direct and inverse proportionality. Three members makes possible to calculate the fourth - unknown member.

  1. Parking
    cars_27 At a building parking, 245 spaces are for cars, 56 are for vans and the rest are for buses. If 14% of all parking spaces are for buses, how many parking spaces are there in the building? How many spaces are for buses?
  2. Octane value
    fuel_7 I loaded 10L 95 octane gasoline and 5L 100 octane gasoline. What is the resulting octane value of the gasoline in the tank?
  3. Transformer
    trafo Solve the textbook problems - transformer: a) N1 = 40, N2 = 80, U2 = 80 V, U1 =? b) N1 = 400, U1 = 200 V, U2 = 50 V, N2 =?
  4. Supermarket
    vaha_17 In a local supermarket, 3/5 kilogram of squid costs 156.00. How do 4 kilograms of squid cost?
  5. Garden
    garden_1 Area of square garden is 6/4 of triangle garden with sides 56 m, 35 m and 35 m. How many meters of fencing need to fence a square garden?
  6. Chocolate
    cokolada Ricky bought 9 same chocolates for 9 Eur. How many euros he pay for 26 chocolates?
  7. Forestry workers
    forestry_workers In the forest is employed 43 laborers planting trees in nurseries. For 6 hour work day would end job in 35 days. After 11 days, 8 laborers go forth? How many days is needed to complete planting trees in nurseries by others, if they will work 10 hours a da
  8. Bonus
    moeny Gross wage was 527 EUR including 16% bonus. How many EUR were bonuses?
  9. Troops
    regiment 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?
  10. Motion problem
    dragway 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?
  11. Excavation
    vykop_ryha 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?
  12. Cyclist
    cyclist_2 A cyclist passes 88 km in 4 hours. How many kilometers he pass in 8 hours?
  13. Beer
    piva After three 10° beers consumed in a short time there are 5.1 g of alcohol in 5 kg adult human blood. How much is it per mille?
  14. Store
    pave One meter of the textile were discounted by 2 USD. Now 9 m of textile cost as before 8 m. Calculate the old and new price of 1 m of the textile.
  15. Motion
    cyclist_1 If you go at speed 5.1 km/h, you come to the station 37 minutes after leaving train. If you go by bike to the station at speed 28 km/h, you come to the station 38 minutes before its departure. How far is the train station?
  16. River
    kongo_river Calculate how many promiles river Vltava average falls, if on section long 928 km flowing water from 1592 m AMSL to 108 m AMSL.
  17. Server
    p_pro Calculate how many average minutes a year is the web server is unavailable, the availability is 99.99%.
  18. Cuboid
    cuboid_1 The cuboid has a surface area 1771 cm2, the length of its edges are in the ratio 5:2:4. Calculate the volume of the cuboid.
  19. Blood
    krv In human body the blood is about 7.2% body weight. How many kilograms of blood is in the human body with weight 93 kg?
  20. Chickens
    chickens 2 chickens give 2 eggs in 2 days. How many eggs can give 8 chickens for 8 days?

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