Statistics - problems

  1. Three painters
    workers_37 The three painters have painted bridge. The first would work done in 5 days, the second in 6 days, and the third in 7 days. How long will the bridge work if they work together?
  2. House numbering
    byty_1 The residential house has three entrances numbered even numbers, successive immediately behind. The sum of the two numbers on the outside entrances is 68. Calculate the middle of these three numbers.
  3. Three pumps
    watertank_2 The water tank is emptied with the first pump in 6 hours, with the second pump in 2 hours. In order to be emptied in 1 hour, all three pumps had to be started at once. How long will take tank be emptied by only the third pump?
  4. Pool
    pool If water flows into the pool by two inlets, fill the whole for 18 hours. First inlet filled pool 10 hour longer than second. How long pool is filled with two inlets separately?
  5. Logic
    blue-barrel A man drinks a barrel of water for 39 days, woman for 64 days, for how many days they drink barrel together?
  6. Coffee
    coffe In stock are three kinds of branded coffee prices: I. kind......6.9 USD/kg II. kind......8.1 USD/kg III. kind.....10 USD/kg Mixing these three species in the ratio 8:6:3 create a mixture. What will be the price of 1100 grams of this mixture?
  7. Transforming cuboid
    cube Cuboid with dimensions 10 cm, 17 and 17 cm is converted into a cube with the same volume. What is its edge length?
  8. Area of RT
    right_triangle_sepia Calculate the area of a right triangle which hypotenuse has length 18 and one hypotenuse segment has lenght 8.
  9. Vinegar 2
    ocet How many percentage of getvinegar solution, if we mix to 12 liters of 4.3% and 1 liters of 3.7% vinegar?
  10. Tractors
    tractors Fields go plow two tractors with various performance. The first tractor plow whole field in 20 hours, the second tractor plow whole field 30 hours déle. How long take plow whole field with two tractors?
  11. Cyclist
    1cyclist Cyclist goes uphill 10 km for 50 minutes and downhill minutes for 29 minutes, both applied to the pedals same force. How long he pass 10 km by plane?
  12. Water
    tanks Mix 20 l of water with temperature of 53 °C, 27 l warm of 86 °C and 11 l water of 49 °C. What is the temperature of the mixed water immediately after mixing?
  13. Car
    american-cars Car goes from point A to point B at speed 86 km/h and back 53 km/h. If they goes there and back at speed 67 km/h trip would take 10 minutes shorter. What is distance between points A and B?
  14. Daily average
    weather_forecast Calculate the average temperature during the day, when 13 hours was 22 °C and 11 hours was 17 °C.
  15. Pedestrian up-down hill
    peak Pedestrian goes for a walk first at plane at 4 km/h, then uphill 3 km/h. Then it is in the middle of the route, turns back and goes downhill at speed 6 km/h. Total walk was 6 hours. How many kilometers went pedestrian?
  16. TV fail
    old_tv The TV has after 10,000 hours average 25 failures. Determine the probability of TV failure after 200 hours of operation.
  17. Inflation
    tsar Once upon a time, tsar owned a money printer and printed and printed. The result of printing money prices went up,in the first year 3.9 %, in the second 6%, in the third 4.7% and in the fourth 5.5%. Then tsar was failed in election. Calculate the aver
  18. Workers
    two_workers Workers A and B will done work together for 15 days. They worked together 13.5 days. Then A worker became ill and worker B finish the job alone for 7.5 days. If every worker was working alone, how many days took whole work for worker A and B?
  19. Workers
    workers Two workers fulfill a certain task when working together for 8 days, the first if he worked himself done work in 15 days. How many days will do whole job a second worker?
  20. Garden
    garden_2 Father dig up the garden in 9 hours. Son in 13 hours. How many hours take dig up the garden together?

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