Examples for 8th grade - page 48

  1. Suit
    oblek The suit cost 218 euros. How much cost the pants if it is 40% cheaper than the jacket.
  2. Balls
    kulicky Michal said to Martin: give me one ball and I'll have twice as you. Martin said: give me 9 and we will have equally. How many balls each have?
  3. Count of roots
    eggs How many solutions has equation x. y = 2531 with two unknowns on the set of natural numbers?
  4. Pure quadratic equation
    kvadrat Solve pure quadratic equation ?.
  5. Axial section
    cone2 Axial section of the cone is equilateral triangle with area 300 m2. Calculate volume of the cone.
  6. Pentagon
    5gon Calculate the area of regular pentagon, which diagonal is u=14.
  7. Mast
    stoziar Mast has 9 m long shadow on a slope rising from the mast foot in the direction of the shadow angle at angle 9.8°. Determine the height of the mast, if the sun above the horizon is at angle 36°6'.
  8. Binomials
    two_persons To binomial ? add a number to the resulting trinomial be square of binomial.
  9. Sphere fall
    sphere How many percent fall volume of sphere if diameter fall 5×?
  10. Z7-I-4 stars 4949
    hviezdicky_mo Write instead of stars digits so the next write of product of the two numbers to be valid: ∗ ∗ ∗ · ∗ ∗ ∗ ∗ ∗ ∗ ∗ 4 9 4 9 ∗ ∗ ∗ ∗ ∗ ∗ 4 ∗ ∗
  11. Two sisters
    cd_disc Two sisters together have 54 CDs. 6/8 CDs has younger sister and is equal to 3/5 of CDs older sisters. How many CDs has each of the sisters?
  12. Price saleoff
    2digits_1 Shoes standing y euros. At first they were discounted by 12% and then 50% of the new amount. After this double cheapening the cost was exactly 22 euros. Determine the original price of shoes.
  13. Blueberries
    blackberries Miko and Anton have a total of 1,580 blueberries. Miko and Anton have them in the ratio 2: 3. Determine how much each of them has.
  14. Regular triangular prism
    3b_hranol Calculate the surface area of body of regular triangular prism, when the length of its base edge is 6.5 cm and height 0.2 m.
  15. Potatoes bags
    vrece_zemiakov I have three bags with 21 kg potatoes. The first bag is 5.5 kg more than in the second bag and the third is 0.5 kg more than in the second bag. Determine how many kgs of potatoes is in each bag.
  16. Middle segment
    priecka In a triangle ABC with the side /AB/ = 24 cm is constructed middle segment /DE/ = 18 cm parallel to the side AB at a distance 1 cm from AB. Calculate the height of the triangle ABC to side AB.
  17. Angles of a triangle
    triangles_9 In the triangle ABC, the angle beta is 15° greater than the angle alpha. The remaining angle is 30° greater than the sum of the angles alpha and beta. Calculate the angles of a triangle.
  18. Roses
    zahon-s-ruzemi On the large rosary was a third white, half red, yellow quarter and six pink. How many roses was in the rosary?
  19. Unknown number
    5nums_1 Determine the unknown number, which double of its fourth square is equal the fifth its square.
  20. Boots
    vysoke-cizmy Master shoemaker has three apprentices. First do one pair of boots for two days, second for 1 day, third on 1.5 day. If they worked together, for how long it would take made a couple of boots?

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