Examples for 8th grade - page 52

  1. The pot
    hrniec_1 Diameter of the pot 38 cm. The height is 30 cm. How many liters of water can fit in the pot?
  2. Pine
    trees How much of a mixed forest rangers want to cut down, if their head said: "We only cut down pine trees, which in our mixed forest 98%. After cut pine trees constitute 94% of all trees left."
  3. Grandmother's clocks
    kukuckove-hodiny Grandmother's clock is late every hour by half a minute. Grandmother it by set exactly at 8.00 am. How many hours will show after 24 hours.?
  4. Mean
    integrales if the mean of the set of data 5, 17, 19, 14, 15, 17, 7, 11, 16, 19, 5, 5, 10, 8, 13, 14, 4, 2, 17, 11, x is -91.74, what is the value of x?
  5. Cube from sphere
    sphere_cube What largest surface area (in cm2) can have a cube that was cut out of a sphere with radius 43 cm?
  6. Rotating cone
    kuzel_3 Calculate the volume and the surface area of a rotating cone of base radius r = 2.3 dm and a height h = 46 mm.
  7. Rhombus A2p
    kosostvorec Rhombus area is 13 cm2 and its height is 5cm long . Determine a perimeter of this rhombus.
  8. Stone
    kamen When Peter threw stone in a box of water he discovered that the water level has risen by 9 cm. The box has a cuboid shape, the bottom has dimensions of 24 cm and 14 cm, height is 50 cm. What volume has a stone?
  9. Water pool
    water What water level is in the pool shaped cuboid with bottom dimensions of 25 m and 10 meters, when is 3750hl water in the pool.
  10. Stock
    frac Enterprise sold 7/12 of their products to foreign markets and 2/5 of the remainder sold at home. How many % of the products is still in stock?
  11. Legs
    zidle In the room are four-legged chairs, three-legged stool, and all are sitted with (one) people. I counted all the leg room and there were a total of 39. How many are there chairs, stool and people?
  12. Wheel
    wheel_1 What is the wheel diameter if on the 0.38 km track turns 128 times?
  13. Fifth of the number
    numbs_5 The fifth of the number is by 24 less than that number. What is the number?
  14. Parachutists
    parasutism Parachutists during freefall firstly held in groups of 4, then of 6, then 9, 12 and finally of 18 members. How many parachutists jump at least should be, if at each group must all be involved.
  15. Euros
    fractal_1 Michal, Peter, John and Lenka got together 2,400 euros. They share an amount in ratio 2:6:4:3. How many got each of them?
  16. Tower model
    tower Tower height is 300 meters, weight 8000 tons. How high is the model of the tower weight 1 kg? (State the result in the centimeters). The model is made from exactly the same material as the original no numbers need to be rounded. The result is a three-digi
  17. Crown coins
    coins_1 Jana saves two-crown and five-crown coins. She has ten coins in the cashier. How many two crowns and how many five crowns shw have if she saved 29 crowns?
  18. Scouts
    skauti_2 Scouts purchased for camp cans two types total cost 1460 CZK. First cans were for CZK 32 and second for 25 CZK. How many cans purchased each type?
  19. Profits
    podnikavec Two members will make profit 52 000, - EUR. The forst earned 8% more and the second 10% more and thus earned together 56 700, - EUR. How many will initially each earn?
  20. Tiler
    asdasd On what surface m2 tiler must lay 30 square tiles, each of which has a side 25 cm?

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