Rational numbers - examples

  1. On the trip
    skola_17 On the trip were more than 55 children, but less than 65 children. Groups of 7 could be formed, but groups of 8 no. How many children were on a trip?
  2. Double 5
    numbers2_49 Peter was thinking of a number. Peter doubles it and gets an answer of 8.6. What was the original number?
  3. Morning
    clocks2_21 Jana rose in the morning in the quarter to seven. She slept nine and a half hours. When did she go to sleep?
  4. Bonus
    moeny Gross wage was 527 EUR including 16% bonus. How many EUR were bonuses?
  5. 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?
  6. 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?
  7. 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?
  8. Logic
    blue-barrel A man drinks a barrel of water for 32 days, woman for 54 days, for how many days they drink barrel together?
  9. Beer
    piva After three 10° beers consumed in a short time there are 5.6 g of alcohol in 6 kg adult human blood. How much is it per mille?
  10. Diophantus
    diofantos_1 We know little about this Greek mathematician from Alexandria, except that he lived around 3rd century A.D. Thanks to an admirer of his, who described his life by means of an algebraic riddle, we know at least something about his life. Diophantus's youth l
  11. Coffee
    coffe In stock are three kinds of branded coffee prices: I. kind......248 Kč/kg II. kind......134 Kč/kg III. kind.....270 Kč/kg Mixing these three species in the ratio 10:7:7 create a mixture. What will be the price of 1100 grams of this mixture?
  12. 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.
  13. Motion
    cyclist_1 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?
  14. Hands
    soviet_watch The clock shows 12 hours. After how many minutes will agle between hour and minute hand 90°? Consider the continuous movement of both hands hours.
  15. Medicament
    tablets Same type of medicament produces a number of manufacturers in a variety of packages with different content of active substance. Pack 1: includes 60 pills of 600 mg of active substance per pack cost 9 Eur. Pack 2: includes 150 pills of 500 mg of active sub
  16. River
    kongo_river Calculate how many promiles river Dunaj average falls, if on section long 957 km flowing water from 1454 m AMSL to 101 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 7705 cm2, the length of its edges are in the ratio 1:4:5. Calculate the volume of the cuboid.
  19. Pool
    swimming-pool The swimming pool is 4 m wide and 9 m long and 158 cm deep. How many hectoliters of water is in it, if the water is 27 cm below its upper edge.
  20. Scale
    pool_1 Swimming pool is long 110 m and 30 m wide. The plan of the city is shown as a rectangle with area 8.25 cm2. What scale is the city plan?

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