Examples for 8th grade - page 32

  1. Trapezoid MO-5-Z8
    lichobeznik_mo_z8 ABCD is a trapezoid that lime segment CE divided into a triangle and parallelogram as shown. Point F is the midpoint of CE, DF line passes through the center of the segment BE and the area of the triangle CDE is 3 cm2. Determine the area of the trapezoid A
  2. Two workers
    workers_2 Two workers carry will do certain work for 12 days. After 8 days of working was one removed, and then the other finished the job alone in 10 days. For how many days would do this work alone each worker?
  3. Katy MO
    reporter_saved6 Kate draw triangle ABC. Middle of AB have mark as X and the center of the side AC as Y. On the side BC wants to find the point Z such that the content area of a 4gon AXZY was greatest. What part of the triangle ABC can maximally occupy 4-gon AXZY?
  4. Chalet
    turancar_autobus The children were on a school trip to the mountain . One third of the journey went by the train and continue by bus. When you get off the bus, they remained a third of the distance they traveled by bus. What part of journey children went by the bus (wrote
  5. Divers
    diving 24-member group of divers carries the air for 11 hours of diving. 4 members of the expedition sick or wasn't came. How many hours is sufficient air to other divers?
  6. Volume and surface
    image001(1) Calculate the volume and surface area of the cylinder when the cylinder height and base diameter is in a ratio of 3:4 and the area of the cylinder jacket is 24 dm2.
  7. Squaring the Circle
    SquareCircle Calculating side of the square with the same area as the circle of radius 18.
  8. Swimming pool 4
    bazen_1 The pool shaped cuboid measuring 12.5 m × 640 cm at the bottom is 960hl water. To what height in meters reaches the water level?
  9. Mushrooms from the forest
    dubak Magda and Tereza goes to pick mushrooms. Total found 70 mushrooms. Magda found that between fungi found 5/9 bedel. Tereza discovered that she found among fungi are 2/17 champignons. How many mushrooms found Magda?
  10. Trapezoid
    hexphitri Area of trapezoid is 135 cm2. Sides a, c and height h are in a ratio 6:4:3. How long are a,c and h? Make calculation...
  11. Words
    words How many 3 letter "words" are possible using 18 letters of the alphabet? a) n - without repetition b) m - with repetition
  12. Snowman
    snehuliak_1 In a circle with a diameter 41 cm are drawn 3 circles /as a snowman/ where: its diameters are integers, each larger circle diameter is 3 cm larger than the diameter of the previous circle. Determine snowman height if we wish highest snowman.
  13. A family
    smetiarske_auto A family of four pays for garbage collection per year 1800 Kč. How many crowns a year the waste company get from the house where lives 93 people?
  14. Seven-segmet
    7segment Lenka is amused that he punched a calculator (seven-segment display) numbers and used only digits 2 to 9. Some numbers have the property that their image in the axial or central symmetry was again give some number. Determine the maximum number of three-d
  15. Vectors
    vectors Vector a has coordinates (7; 16) and vector b has coordinates (15; -7). If the vector c = b - a, what is the magnitude of the vector c?
  16. Tournament
    turnaj Determine how many ways can be chosen four representatives from 27 students to school tournament.
  17. Reflector
    lamp Circular reflector throws light cone with a vertex angle 60° and is on 22 m height tower. The axis of the light beam has with the axis of the tower angle 24°. What is the maximum length of the illuminated horizontal plane?
  18. Friends in cinema
    cinema_1 5 friends went to the cinema. How many possible ways can sit in a row, if one of them wants to sit in the middle and the remaining's place does not matter?
  19. Permill
    permille How many permill is 1931 from 166456?
  20. Cross-country competition
    spartakiada Cross-country competition was attended by 76% of pupils of class 9.B. Class consis of 16 boys, two of whom did not run and 4 girls did not run. How many girls go to class 9.B?

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