Examples for 8th grade

  1. Rectangular base pyramid
    jehlan_4b_obdelnik Calculate an area of the shell of the pyramid with a rectangular base of 2.8 m and 1.4 m and height 2.5 meters.
  2. Hexa pyramid
    hexa_pyramid_1 The base of the regular pyramid is a hexagon, which can be described by a circle with a radius of 1 m. Find the volume of the pyramid 2.5 m high.
  3. Triangular prism
    prism3 Calculate the surface of a triangular prism with the base of an equilateral triangle with a side length of 7.5 cm and a corresponding height of 6.5 cm. Prism height is 15cm.
  4. Two accounts
    bankovka Two accounts in the bank, one per year interest 2%, the second 3%. Total interest income 1900 USD. If interest rates were reversed, the yield would be USD 200 higher. What are the amounts on each account?
  5. Buttons
    oblek Men's shirt has sewn 9 buttons and blouse 3 buttons. Together they sewed 60 pieces and consumed 390 buttons. How many shirts?
  6. The fastest
    ship The fastest boat can reach speeds more than 710% as fast as the Queen Mary 2. How would you express this number as a fraction and as a decimal?
  7. Squares above sides
    pataVysky Two squares are constructed on two sides of the ABC triangle. The square area above the BC side is 25 cm2. The height vc to the side AB is 3 cm long. The heel P of height vc divides the AB side in a 2: 1 ratio. The AC side is longer than the BC side. Calc
  8. Calculate
    hranol Calculate the surface of a regular quadrilateral prism whose base edge is 2.4dm and the height of the prism is 38cm.
  9. The prison ball
    prisonBall Calculate the density of the material that the prison ball is made from if you know its diameter is 15cm and its weight is approximately 2.3kg. With the help of mathematical-physicochemical tables estimate what material the ball is made from.
  10. Possible combinations - word
    dices2 How many ways can the letters F, A, I, R be arranged?
  11. Two bodies
    cylinders The rectangle with dimensions 8 cm and 4 cm is rotated 360º first around the longer side to form the first body. Then, we similarly rotate the rectangle around the shorter side b to form a second body. Determine the ratio of surfaces of the first and seco
  12. Cross five
    5squares2 The figure on the picture is composed of the same squares and has a content of 45cm². What's its perimeter?
  13. Two accounts
    bank A banker divided $5000 between 2 accounts, one paying 10% annual interest and the second paying 8% annual interest. Express the amount invested in the 10% account in the terms of the amount invested in the 8% account.
  14. Milk
    cow There were 22 liters of milk in three containers. There was 6 liters more in the first container than in the second. After pouring 5 liters from the first container into the third container, the same quantity of milk is in the second and third container.
  15. Two trains
    trains Two trains departed from City A and City B against each other. They met after some time. The first train then took 9 hours to reach city B, and the second train took 4 hours to reach city A. In what proportion were the train speeds?
  16. Length of the edge
    cube_shield Find the length of the edge of a cube that has a cm2 surface and a volume in cm3 expressed by the same number.
  17. The Indian tent
    indian_stan The Indian tent is cone-shaped. Its height is 3.5 m. The diameter of the base is 2.5 m. How much canvas is needed to make a tire?
  18. Unknown number
    percent 15% of the unknown number is 18 less than 21% of the same number. What is the unknown number?
  19. Perimeter of the circle
    squares Calculate the perimeter of the circle in dm, whose radius equals the side of the square containing 0.49 dm2?
  20. Scholarship
    coins The annual scholarship of the best student and second-best student in the class is 3500 euros in total. The best student scholarship in 8 months is the same as the second-best student scholar in the class for the whole year. How big is the annual scholars

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