8th grade (13y) + direct relationship - examples

  1. Pool
    pool 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?
  2. Forestry workers
    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
  3. Bonus
    moeny Gross wage was 1762 USD including 22% bonus. How many USD were bonuses?
  4. Excavation
    vykop_ryha 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?
  5. Beer
    piva After three 10° beers consumed in a short time there are 5.2 g of alcohol in 6 kg adult human blood. How much is it per mille?
  6. Coffee
    coffe In stock are three kinds of branded coffee prices: I. kind......5.3 USD/kg II. kind......11.6 USD/kg III. kind.....5.8 USD/kg Mixing these three species in the ratio 2:8:3 create a mixture. What will be the price of 800 grams of this mixture?
  7. Server
    p_pro Calculate how many average minutes a year is the web server is unavailable, the availability is 99.99%.
  8. Cuboid
    cuboid_1 The cuboid has a surface area 3380 cm2, the length of its edges are in the ratio 4:3:1. Calculate the volume of the cuboid.
  9. Gimli Glider
    gimli_glider Aircraft Boeing 767 lose both engines at 45000 feet. The plane captain maintain optimum gliding conditions. Every minute, lose 2080 feet and maintain constant speed 196 knots. Calculate how long takes to plane from engines failure to hit ground. Calculate
  10. 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 13200 cm2. What scale is the city plan?
  11. ŽSR
    luzianky Calculate fixed annual personnel costs of operating monorail line 106 km long if every 5 km is station, which serve three people - one dispatcher and two switchman in 3-shift operation. Consider the average salary of the employee 847 €.
  12. Cyclist
    1cyclist Cyclist goes uphill 1 km for 6.3 minutes and downhill minutes for 2.1 minutes, both applied to the pedals same force. How long he pass 1 km by plane?
  13. Engineer Kažimír
    demagog_smer_1 The difference between politicians-demagogues and reasonable person with at least primary education beautifully illustrated by the TV show example. "Engineer" Kažimír says that during their tenure there was a large decline in the price of natural gas, pri
  14. Road repair
    workers_1 Road repair took 16 days for 34 workers if they worked 6 hours a day. How many days take repair same road 33 workers if they work 6 per day?
  15. Gear
    ozubene_kolesa Two gears, fit into each other, has transfer 1:5. Centres of gears are spaced 28 cm. What are the radii of the gears?
  16. Radians
    pi_text Convert 54° to radians. Write result as multiple of number π.
  17. Expansion
    magnification If one side of the rectangle is larger 3-times and second 4-times, what percentage increases the area of rectangle?
  18. Arc
    arc_1 Circle arc corresponding to angle is 193° is 23 dm long. What is the length of the entire circle?
  19. Pediatrician
    doctor Pediatrician this month of 21 working days takes 3 days holidays. What is the probability that on Monday will be at work?
  20. Car range
    Lupo_3L_TDI.JPG Calculate the maximum range of car, if you can spend 25 euros, price of diesel is 1.55 Eur/l and car consumption is 6.4 l/100 km.

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