Examples for 8th grade - page 62

  1. Paul and Honza
    tchata Honza went to chat on a bike without a break 3.0 hours. Paul the same way without breaks 30 minutes longer. The difference between the speeds of the two boys was the one kilometer per hour. How fast was Paul, if you know that the speed of the boys did not.
  2. Wheel
    wheel_1 What is the wheel diameter if on the 0.42 km track turns 115 times?
  3. The body
    body_cubes The body on the figure consists of cubes with an edge length 10 cm. What surface has this body?
  4. Trousers
    trousers Jarek bought new trousers, but the trousers were too long. Their length was in the ratio 5: 8 to Jarek height. Mother his trousers cut by 4 cm, thus the original ratio decreased by 4%. Determine Jarek's high.
  5. Sinus
    sine_cosine Determine the smallest integer p for which the equation 5 sin x = p has no solution.
  6. Pigs
    prasce Pigs are feed by beet.Beet feed containing 12% dry solids, which is 0.66% of digestible crude protein. How much beet must beconsumed in one month (30 days), if the weight of digestible crude protein contained in a daily dose of beet was 0.688 kg?
  7. Aircrafts
    boeings Above the town hall tower flew the plane with constant speed 508 km/h and 15 minutes later the second plane at speed of 651 km/h. How long and how far from the town hall will be aircrafts caught up?
  8. Inscribed rectangle
    circle_desc_rectangular The circle area is 184. Determine the area of inscribed rectangle with one side 10 long.
  9. ISO trapezium
    trapezium_2 Calculate area of isosceles trapezoid with base 53 long, leg 43 long and with the angle between the base and leg 70 degrees.
  10. Ethnicity
    indian Share of ethnicity XY is 10%, which is 1/9 more than in the prewar period. What was the share of that ethnicity in the pre-war period?
  11. Circle section
    circle_segment Equilateral triangle with side 50 is inscribed circle section whose center is in one of the vertices of the triangle and the arc touches the opposite side. Calculate: a) the length of the arc b) the ratio betewwn the circumference to the circle sector.
  12. Three workers
    three_workers Three workers A, B, C have to work on a specific task. Workers A and B completed whole task in 25 days, B together with C for 16 days, A together with C for 10 days. How long it would take to complete the task every one of them alone? How long it would.
  13. Icerink
    klzisko-korcule Rectangular rink with dimensions of 79.5 m and 529 dm must be covered with a layer of ice 4.5 cm thick. How many liters of water is necessary for the formation of ice when the volume of ice is 10.9% greater than the volume of water.
  14. Tower
    cone_roof How many m2 of copper plate should be to replace roof of the tower conical shape with diameter 13 m and the angle at the vertex of the axial section is 150°?
  15. Silo
    silo Outer perimeter of silo is 24 m. Concrete wall is 18 cm thick. What is diameter and area of inside floor of silo?
  16. Prism
    3b_hranol Right angle prism, whose base is right triangle with leg a = 3 cm and hypotenuse c = 5 cm has same volume as a cube with an edge length of 1 dm. a) Determine the height of the prism b) Calculate the surface of the prism c) What percentage of the cube'
  17. Sines
    sines In ▵ ABC, if sin(α)=0.5 and sin(β)=0.1 calculate sin(γ)
  18. Steamship
    parnik Between the two ports on the river is going steamship. The journey there and back takes 14:49. Downstream steamship traveling at 21 km/h, upstream 9 km/h. What is the distance between the ports?
  19. Parallelogram
    paralleogram Calculate area of the parallelogram ABCD as shown if |AB| = 45 cm, |BC| = 23 cm and angle BAD = 30°
  20. Triangle ABC
    triangles_3 Calculate the sides of triangle ABC with area 883 cm2 and if a: b: c = 15:7:19

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