Examples for 8th grade

  1. Even / odd numbers
    parne_neparne a / Using variable n write two consecutive odd numbers. b / the sum of three consecutive odd numbers is 333. What are this numbers?
  2. Hexagon = 8 parts
    stef.6.11.99 Divide the regular hexagon into eight equal parts.
  3. Ages
    age2_1 John, Teresa, Daniel and Paul have summary 56 years. Their ages are in a ratio of 1:2:5:6. Determine how many years have each of them.
  4. Square - increased perimeter
    rectangles_4 How many times is increased perimeter of the square, where its sides increases by 150%? If the perimeter of square will increase twice, how much% increases the content area of the square?
  5. Volume of three cuboids
    image10 Calculate the total volume of all cuboids for which the the size of the edges are in a ratio of 1:2:3, and one of the edges has a size 6 cm.
  6. Tripled square
    squares4_1 If you tripled the length of the sides of the square ABCD you increases its content by 200 cm2. How long is the side of the square ABCD?
  7. Three drivers
    gas_car Three driversdriving the same direction found that they have same amounth of gasoline. The first is enough to go 6 km, 4 km second and third 3km. Gasoline they divided so all three just drove to the nearest petrol station. How many km away was a petrol st
  8. Bricks wall
    tehly_1 There are 5000 bricks. How high wall thickness of 20 cm around the area which has dimensions 20 m and 15 m can use these bricks to build? Brick dimensions are 30 cm, 20 cm and 10 cm.
  9. Triangle KLB
    rovnostranny_trojuholnik It is given equilateral triangle ABC. From point L which is the midpoint of the side BC of the triangle it is drwn perpendicular to the side AB. Intersection of perpendicular and the side AB is point K. How many % of the area of the triangle ABC is area
  10. Desribed circle to rectangle
    rectangle_in_circle_1 Rectangle with sides 6 cm and 4 cm was circumscribed circle. What part of the content of the circle determined by the circumscribed circle occupies a rectangle? Express in perctentages(%).
  11. Rectangle
    obdelnik_1 The length of the rectangle are in the ratio 5:12 and the circumference is 238 cm. Calculate the length of the diagonal and area of rectangle.
  12. Iron cast
    litina What is the weight of cast iron with volume 3575 cubic centimeters. The density of the cast iron is 7600 kg/m3
  13. Find the
    kruh Find the radius of the circular base of the vessel, whose perimeter is 2.51 m. Write the result to one decimal place in meters. Via the π sign - Ludolph's number
  14. Prism
    hranol_3bokovy_1 Find the volume and surface area of prism with base of an equilateral triangle with side 7 dm long and the body height of 1.5 m.
  15. Wood cuboid
    dub What is the weight of the wood cuboid 15 cm, 20 cm, 3 m if 1 m3 wood weighs 800 kg?
  16. Ring
    prsten The ring made from gold and copper alloy has a weight of 14.5 g and a volume of 1.03 cm3. How much gold and how much copper it contains? The metal densities are Au 19.3 g/cm³ and Cu 8.94 kg·dm-3
  17. Decagon prism
    10gon_1 A regular decagon of side a = 2 cm is the base of the perpendicular prism, the side walls are squares. Find the prism volume in cm3, round to two decimal places.
  18. Basket of fruit
    hrusky_jablka In six baskets, the seller has fruit. In individual baskets, there are only apples or just pears with the following number of fruits: 5,6,12,14,23 and 29. "If I sell this basket," the salesman thinks, "then I will have just as many apples as a pear." Whic
  19. Hexa prism
    hexagon Determine the volume of hex prism with edge base 4 cm. The body height is 28 cm.
  20. Freezer
    mraznicka The freezer has the shape of a cuboid with internal dimensions of 12 cm, 10 cm, 30 cm. A layer of ice of 23 mm thick was formed on the inner walls (and on the opening) of the freezer. How many liters of water will drain if we dispose the freezer?

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