Examples for 8th grade

  1. Six years
    children_9 In six years Jan will be twice as old as he was six years ago. How old is he?
  2. Hexagon cut pyramid
    truncated_hexa_pyramid Calculate the volume of a regular 6-sided cut pyramid if the bottom edge is 30 cm, the top edge us 12 cm, and the side edge length is 41 cm.
  3. Father and son
    family_17 Father is 48 years old, son 23. When will be the father twice older than a son?
  4. Cutting circles
    circles2_2 From the square 1 m side we have to cut the circles with a radius of 10 cm. How many discs we cut and how many percent will be waste?
  5. Flowerbed
    garden_16 In the park there is a large circular flowerbed with a diameter of 12 m. Jakub circulated him ten times and the smaller Vojtoseven times. How many meters each went by and how many meters did Jakub run more than Vojta?
  6. Diameter
    circles2_1 What is the inside diameter of the cylinder container and if half a liter of water reaches a height 15 cm?
  7. Fewer than 500 sheep,
    sheep-500 There are fewer than 500 sheep, but if they stand in a double, triple, quadruple, five and sixth order, one sheep will remain. But they can stand in the seventh order. How many are sheep?
  8. Parallelogram +ľ
    rovnobeznik_2.JPG | AB | = 76cm, | BC | = 44cm, angle BAD = 30 °. Find the area of the parallelogram.
  9. Force meter
    archimedes We put the statuette on the force meter. The force meter showed a value 25 N. Then we placed the statuette on the force meter completely immersed in the water. The force meter showed a value 17 N. What is the volume of the statuette?
  10. Hexagonal prism
    hexa_prism The base of the prism is a regular hexagon consisting of six triangles with side a = 12 cm and height va = 10.4 cm. The prism height is 5 cm. Calculate the volume and surface of the prism!
  11. Square circles
    stvorec_kruh Calculate the length of the described and inscribed circle to the square ABCD with a side of 5cm.
  12. Grandfather
    family_16 The grandfather is three years older than an grandmother. The average age of the grandmother, the grandfather and their seven grandchildren is 28 years. The grandchildren have a total of 105 years. Calculate how old is grandfather.
  13. Children pool
    hexagon_prism2 The bottom of the children's pool is a regular hexagon with a = 60 cm side. The distance of opposing sides is 104 cm, the height of the pool is 45 cm. A) How many liters of water can fit into the pool? B) The pool is made of a double layer of plastic film
  14. Candies
    bonbons_10 There are two types of candies in the store at 20 CZK/kg and 80 CZK/kg. How much will be cost a mix if we mix 22kg cheaper and 4kg more expensive candies?
  15. Three numbers
    fun3_8 The sum of the three numbers is 287. These numbers are in a ratio of 3: 7: 1/4 Define these numbers
  16. Wheel diameter
    koleso_1 A 1m diameter wheel rolled along a 100m long track. How many times did it turn?
  17. Czech crown salary
    penize_34 The monthly salary of the employee is CZK 10,800. In the course of the year the bulk salary increased by CZK 500. Calculate which month (1 ... 12) was increased if its annual income was 133,600 CZK.
  18. Isosceles trapezoid
    lichobeznik_mo_z8_5 What is the height of an isosceles trapezoid, the base of which has a length of 11 cm and 8 cm and whose legs measure 2.5 cm?
  19. Prices prices
    textiles The meter of the textille was reduced by CZK 42, so 4 meters of the new price was 20 CZK cheaper than 3 meters of the original price. What was the original and new price of the textille?
  20. Four circles
    circles_2 1) Calculate the circle radius if its area is 400 cm square 2) Calculate the radius of the circle whose circumference is 400 cm. 3) Calculate circle circumference if its area is 400 cm square 4) Calculate the circle's area if perimeter 400 cm.

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