Examples for 8th grade - page 10

  1. Strange x
    pie For what x is true ??
  2. Metallurgical enterprise
    iron_industry Metallurgical company daily produces 873 tons of cast iron. How many tons of coke it burns to melt cast iron when 17 tons of cast consumes 13 tons of coke?
  3. 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
  4. Tissues
    harmasan The store got three kinds of tissues - 132 children, 156 women and 204 men. Tissues each species were packed into boxes after the number of pieces the same for all three types (and greatest). Determine the number, if you know that every box has more than 6
  5. Two doctors
    dr_cvach Doctor A will determine the correct diagnosis with a probability 80% and doctor B with a probability 72%. Calculate probability of correct diagnosis if patient is diagnosed by both doctors.
  6. Coffee
    coffee Coffee from the machine in the cup cost 25 cents. Coffee is 20 cents more expensive than the cup. How much is the cup?
  7. Blueberries
    boruvky Marie earns 1.8 liters of blueberries for 1.2 hours, Peter 2.6 liters for 1.2 hours. How long have earns together one liter?
  8. The bridge
    circle_dam Across the circle lakepasses through its center bridge over the lake. At three different locations on the lake shore are three fishermen A, B, C. Which of fishermen see the bridge under the largest angle?
  9. Cube
    kocka_rubik The cube weighs 18 kg. How weight is cube of the same material, if its dimensions are 3-times smaller?
  10. Eiffel Tower
    eiffel_tower Eiffel Tower in Paris is 300 meters high, is made of steel. Its weight is 8000 tons. How tall is the tower model made ​​of the same material, if it weigh is 4.8 kg?
  11. Mountain railway
    semmering Height difference between points A, B of railway line is 38.5 meters, their horizontal distance is 3.5 km. Determine average climb in permille up the track.
  12. 30-60-90
    30-60-90 The longer leg of a 30°-60°-90° triangle measures 7. What is the length of the shorter leg?
  13. Garden
    garden_1 Area of square garden is 6/7 of triangle garden with sides 96 m, 60 m and 60 m. How many meters of fencing need to fence a square garden?
  14. Square and circles
    kruznica_stvorec_1 Square with sides 82 km is circumscribed and inscribed with circles. Determine the radiuses of both circles.
  15. Coins
    mince_1 On coins found was stated that from the year 87 BC. It is right?
  16. The dice
    hracia-kocka What is the probability of events that if we throw a dice is rolled less than 6?
  17. Rhombus
    rhombus Calculate the perimeter and area of ​​rhombus whose diagonals are 15 cm and 27 cm long.
  18. Crown
    2_kcs Siblings collect a 2-crowns and 5-crowns. Together have 80 coins with a total of value 310 crowns. How many saved two-crowns and how many five-crowns?
  19. Bus vs. train
    bus_vs_train Bus started from point A 15 minutes before the train started from the same place. The bus went an average speed of 49 km/h, train 66 km/h. To point B train and bus arrived simultaneously. Calculate time of train journey, if train and bus travelled the.
  20. Olympics
    olimpiada-medaliile In how many ways can be placed 6 athletes on the podium at the Olympics? Depend on the color of the metal.

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