Examples for 8th grade

  1. Water
    storm_1 On the lawn which has area 914 m2 rained 3 mm of water. How many liters of water rained?
  2. Angles in ratio
    angles_1 The size of the angles of the triangle are in ratio x: y = 7: 5 and the angle z is 42° lower than the angle y. Find size of the angles x, y, z.
  3. Parallelogram
    rovnobeznik_1 Parallelogram has sides lengths in the ratio 3: 4 and perimeter 2.8 meters. Determine the lengths of the sides.
  4. Medians in triangle
    stredne_pricky Median of isosceles triangle has a length 3 cm. Determine the length of its sides if its perimeter is 16 cm.
  5. Angles of the triangle
    angles ABC is a triangle. The size of the angles alpha, beta are in a ratio 4: 7. The angle gamma is greater than the angle alpha by a quarter of a straight angle. Determine angles of the triangle ABC.
  6. Bottles of juice
    juice_cones How many 2-liter bottles of juice need to buy if you want to transfer juice to 50 pitchers rotary cone shape with a diameter of 24 cm and base side length of 1.5 dm.
  7. Painters
    3_painters One painter could paint a school for 7 days. The second one for 6 days. It was necessary to paint the school in two days. Next painter was invited and all worked together. How long would this painter painted the school itself?
  8. Isosceles trapezoid
    rr_licho The lengths of the bases of the isosceles trapezoid are in the ratio 5:3, the arms have a length of 5 cm and height = 4.8 cm. Calculate the circumference and area of a trapezoid.
  9. Coal
    coal If the daily consumption of 1.6 tons of coal, it is sufficient to supply the boiler for 42 days. How long is sufficient to supply when will burn only 1.2 tons of coal a day ?
  10. Feed for horses
    horses In the kennel have feed for two horses for 21 days. The station brought an additional 5 horses. How many days will last the feed for all the horses if they have the same daily ration?
  11. The farmer
    kombajn The farmer harvested 840 tons of grain in 2006, which was 44% less than in 2005, and one-fifth more than in 2004. How many tons of grain harvested in years 2005 and 2004?
  12. Painters
    maliri 15 painters painted fence for 280 minutes. For how many minutes paint half of this fence 12 painters?
  13. Summerjobs
    agentura The agency give summerjobs for 2352 students in 2018. The eighth was high-school students, the rest was undergraduates. How many undergraduates works via agency in 2018?
  14. Seven tractors
    koleso Seven tractor plowed 308 ha field in four days. How many hectares of fields will plowe 9 tractors in 3 days at the same power?
  15. Painting
    natieranie Jožko with Fero painted the bench for four hours. How many hours would take work if four friends help him?
  16. Tailor master
    saty There are less than 50m of textile in the tailoring workshop. When cutting on a blouse (consumption 1.5m), no textile is left. When using a cloth (consumption of 3.2m), no textile is left. How many meters of textile are in a tailor's workshop?
  17. Container
    canister First day got off 1/4 water from full container, second day 1/5 of the remaining water. How many percent remain container filled?
  18. Mukls
    Chinese women workers The working group, in which 6 workers would ordered job completed within 21 working days. How many workers must be accept yet that the contract will be completed in 14 working days?
  19. Wood
    rubanie_dreva Peter chops wood. If they cut down a half hours a day he ended work in 9 days. But Peter needs to end work 3 days earlier. How many minutes a day should cut down?
  20. Five tractors
    tractor_1 Five tractors plow field in 4.8 hours. How long plow this field if after 1.5 hours of work two tractors went to a different field?

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