Examples for 8th grade - page 34

  1. Mushrooms from the forest
    dubak Magda and Tereza goes to pick mushrooms. Total found 70 mushrooms. Magda found that between fungi found 5/9 bedel. Tereza discovered that she found among fungi are 2/17 champignons. How many mushrooms found Magda?
  2. Swimming pool 4
    bazen_1 The pool shaped cuboid measuring 12.5 m × 640 cm at the bottom is 960hl water. To what height in meters reaches the water level?
  3. Triangle
    trangle_nice Calculate heights of the triangle ABC if sides of the triangle are a=75, b=84 and c=33.
  4. ISO Triangle V2
    triangle_3 Perimeter of RR triangle (isosceles) is 474 m and the base is 48 m longer than the arms. Calculate the area of this triangle.
  5. Pennies
    Toliar.preview 800 pennies have the same value as 100 ducats. 100 pennies have the same value as 250 tolars. How many ducats has the same value as 100 tolars?
  6. Again saw
    rectangle_in_circle From the trunk of the tree we have to a sculpture beam with rectangular cross-section with dimensions 146 mm and 128 mm. What is the trunk smallest diameter?
  7. Gon functions
    quadrants Decide which of the numbers (values ​​of trigonometric functions) are positive and which are negative (or zero). Positive mark +1 and negative -1.
  8. Retail
    glasses At what price bought retail 1 kg goods from wholesale, if lost in the distribution is 4% of weight of the goods and retail still have a profit of 6.3%? Goods are sold at retail for 25 euro per kg.
  9. Squaring the Circle
    SquareCircle Calculating side of the square with the same area as the circle of radius 18.
  10. Lathe
    sustruh Calculate the percentage of waste if the cube with 53 cm long edge is lathed to cylinder with a maximum volume.
  11. A family
    smetiarske_auto A family of four pays for garbage collection per year 1800 Kč. How many crowns a year the waste company get from the house where lives 93 people?
  12. Pumps 3
    pump_water Two pumps of the same power fill the garden pool for 10 hours. How many of these pumps would have to use if we want to shorten the filling of the pool to four hours?
  13. Rising price
    book The book first become more expensive by 5 euros. New price was later increased by 8%. After the second price increase book cost 46 euros. What was the original price of the book?
  14. Snowman
    snehuliak_1 In a circle with a diameter 50 cm are drawn 3 circles /as a snowman/ where: its diameters are integers, each larger circle diameter is 3 cm larger than the diameter of the previous circle. Determine snowman height if we wish highest snowman.
  15. Bricks
    cihla_brick Openings in perforated bricks occupy 10% and brick has dimensions 30 cm, 15 cm and 7.5 cm. Calculate a) the weight of a perforated bricks, if you know that the density of the full brick material is p = 1800 kg/m3 (1.8 kg/dm3) b) the number of perforated.
  16. Passenger car
    ts_5_2_wi-1 Passenger car travels 1 km for 2.3 minutes, a truck during a 50 seconds long. How much is the speed of the truck less?
  17. Compare II
    powers Which of the numbers 710, 107 is greater?
  18. Water tank 2
    tank_1 Water tank cuboid is 12 meters long and 6.5 meters wide and 1.2 meters high. How many hectoliters are in the tank when it is filled to 81%?
  19. Ladder
    studna 5.2 meters long ladder is leaning against the wall of the well and its lower end is 1.3 meters from this wall. How high from the bottom of a well is the top edge of the ladder?
  20. Pyramid 8
    ihlan2 Calculate the volume and the surface area of a regular quadrangular pyramid with the base side 9 cm and side wall with the base has an angle 75°.

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