Examples for 8th grade - page 38

  1. TV commercials
    ad_on_TV For the typical one-hour prime-time television slot, the number of minutes of commercials is 3/8 of the minutes of the actual program. Determine how many minutes of the program are shown in that one hour.
  2. Hiker and cyclist
    cyklo At 7 PM hiker started at 6 km/h to hike. After 3 hrs. later started on the same trip cyclist at speed of 15 km/h. After an hour of driving a flat tire and take him half hours to correct defect. At what time catch up cyclist with hiker?
  3. Ratio
    ratio_2 Unfold number 1963 in the ratio 9:2:2.
  4. Distance
    origin_math Wha is the distance between the origin and the point (18; 22)?
  5. Glass
    glass Peter broke the window glass with size 110 cm and 90 cm. 1 square meter of glass costs 11 USD. How much money is need to pay for a new glass?
  6. Pot
    valec_hrnec Calculate the height of 3 liter pot with shape cylinder with a diameter of 10 cm.
  7. Rope
    navijak How many meters of rope 10 mm thick will fit on the bobbin diameter of 200 mm and length 350 mm (central mandrel have a diameter 50 mm)?
  8. Bases
    trapezoids_1 The length of the bases trapezium are in ratio 4:5. Length of midline is 15. How long are the bases of a trapezoid?
  9. Journey
    ud2 Charles and Eva stands in front of his house, Charles went to school south at speed 5.4 km/h, Eva went to the store on a bicycle eastwards at speed 21.6 km/h. How far apart they are after 10 minutes?
  10. Scouts
    icons Three scouts went on a three day trip. The second day went 4 km more than the first day. The third day went two times less than the first day. They went along 54 km. How many kilometers went every day together?
  11. Pocket
    bageta Mirka spent on a trip for gifts half pocket. For the third remain money bought a bagel. Six euros left her. How many euros had Mirka in pocket?
  12. Clocks
    clock+ What distance will describe the tip of minute hand 6 cm long for 20 minutes when we know the starting position with finally enclose hands each other 120°?
  13. Cubes
    kocky_1 Most how many cubes with an edge length of 5 cm may fit in the cube with the inner edge of 0.4 m?
  14. Hop-garden
    chmelnica The length of the rectangular hop garden Mr. Smith increased by 25% and its width by 30%. What is the percentage change in area of hop garden?
  15. Window
    buranie_otvoru Peter demolish box hole in the wall for window frame 147×51 cm. When they came masters fitted frame and window will be found that glass is 13.3 cm from the hole in each direction. Calculate how much percent less light enters the window than hole?
  16. Cuboid aquarium
    cuboid Cuboid 25 times 30 cm. How long is third side if cuboid contains 30 liters of water?
  17. Trough
    amazonka How many liters of water per second can go via trough, which has a cross section of semicircle with radius 2.5 m and speed of water is 147 cm per second?
  18. Sheep
    ships Shepherd tending the sheep. Tourists asked him how much they have. The shepherd said, "there are fewer than 500. If I them lined up in 4-row 3 remain. If in 5-row 4 remain. If in 6-row 5 remain. But I can form 7-row." How many sheep have herdsman?
  19. Annulus
    medzikruzie.JPG Two concentric circles form an annulus of width 10 cm. The radius of the smaller circle is 20 cm. Calculate the content area of annulus.
  20. Similarity
    rectangles_1 Rectangle ABCD has dimensions of 7 cm and 6 cm. Rectangle PQRS has dimensions 14 cm and 12 cm. Determine coefficient of the similarity k of the rectangles, if they aren't similar enter zero as the coefficient of similarity.

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