Examples for 8th grade - page 50

  1. Silver medal
    circle_1 To circular silver medal with a diameter of 10 cm is inscribed gold cross, which consists of five equal squares. What is the content area of silver part?
  2. 9-gon
    9gon Sum of interiol angles of 9-gon is:
  3. Children
    weight_1 Margaret and Zdena weighs the same and Petra 3 kg more. Together weigh 156 kg. How much does they weigh?
  4. Car consumption
    motor The car has consumption 4 l/100 km. How much money will it cost ride 4 km in long if diesel price is 1.53 USD/l?
  5. Cube 7
    krychle_4 Calculate the volume of a cube, whose sum of the lengths of all edges is 276 cm.
  6. Seamstress
    krajcirka Seamstress bought two kinds of textile together 25 meters. One at 50 SKK and the second 70 SKK per meter. How many meter bought from this two textiles when paid totally 1540 SKK?
  7. Janitor
    snow Janitor tosses 26 cm layer of snow on the school grounds for 90 minutes. How many friends would have to call for help if snow needs to have bowled for 15 minutes. We assume that at the same time bow all the same amount of snow.
  8. Wheel diameter
    koleso_1 A 1m diameter wheel rolled along a 100m long track. How many times did it turn?
  9. 12 Moons
    12_mesicku Good Marry came to ask twelve moons for help with collecting strawberries. All twelve moons 1200 strawberries picked in 20 minutes. But lazy months July and August cease tear after 5 minutes. How many minutes in total will take collect strawberries?
  10. 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.
  11. Cylinder
    cyl_1 The cylinder-shaped container has 80 liters of water. The water reaches 45 cm height. How many liters of water will be in a container if water level extend to a height 72 cm? Write the result in liters, write down only as a whole or decimal number.
  12. Feed for horses
    horses In the kennel have feed for two horses for 21 days. The station brought an additional 5 horses. How many days will last the feed for all the horses if they have the same daily ration?
  13. Crowns
    money_4 1180 crowns is divided into three people that A got 20% less than B and C by 15% more than B. How many got A,B and C?
  14. Jane and Miro
    two_men Jane brother Miro is 42 years. And he is three times old as it was Jane when Miro was for so many years as there are now Jane. How old is Jane?
  15. Ring
    prsten The ring made from gold and copper alloy has a weight of 14.5 g and a volume of 1.03 cm3. How much gold and how much copper it contains? The metal densities are Au 19.3 g/cm³ and Cu 8.94 kg·dm-3
  16. Smallest internal angle
    angles_3 Calculate what size has the smallest internal angle of the triangle if values of angles α:β:γ = 3:4:8
  17. Three siblings
    brothers Three siblings have birthday in one day-today. Together they have 35 years today. The youngest is three years younger than middle and the oldest is 5 years older than middle. How old is each?
  18. Square vs rectangle
    ctverec Square and rectangle have the same area contents. The length of the rectangle is 9 greater and width 6 less than side of the square. Calculate the side of a square.
  19. Cuboid walls
    cuboid_9 Calculate the volume of the cuboid if its different walls have area of 195cm², 135cm² and 117cm².
  20. Disease
    kravy Farmers'cooperative had a supply of feed for 50 cows to 6 days. Cows got insidious disease after 4 days, 10 of them died. How many total days that farmers had feed for cows?

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