Examples for 8th grade - page 9

  1. Daily average
    weather_forecast Calculate the average temperature during the day, when 13 hours was 22 °C and 11 hours was 17 °C.
  2. Cu thief
    trolleywire_1 The thief stole 122 meters copper wire with cross-section area of 95 mm2. Calculate how much money gets in the scrap redemption, if redeemed copper for 5.5 eur/kg? The density of copper is 8.96 t/m3.
  3. Lathe
    soustruh From the cube of edge 37 cm was lathed maximum cylinder. What percentage of the cube is left as waste after lathed?
  4. Arc
    arc_1 Circle arc corresponding to angle is 32° is 28 dm long. What is the length of the entire circle?
  5. Sea water
    sea Mixing 34 kg of sea water with 34 kg rainwater is created water containing 3.4% salt. How many percent sea water contains salt?
  6. Pedestrian up-down hill
    peak Pedestrian goes for a walk first at plane at 4 km/h, then uphill 3 km/h. Then it is in the middle of the route, turns back and goes downhill at speed 6 km/h. Total walk was 6 hours. How many kilometers went pedestrian?
  7. Medians
    medias_triangle Calculate the sides of a right triangle if the length of the medians to the legs are ta = 21 cm and tb=12 cm.
  8. Floating barrel
    floating_barrel Barrel (cylinder shape) floats on water, top of barrel is 8 dm above water and the width of surfaced barrel part is 23 dm. Barrel length is 24 dm. Calculate the volume of the barrel.
  9. Kites
    drake Boys run kite on a cable of 68 meters long. What is the kite altitude, if the angle from the horizontal plane is 72°?
  10. Described
    desc_circle Calculate perimeter of the circle described by a triangle with sides 478, 255, 352.
  11. Circular pool
    arc_open The base of pool is circle with a radius r = 10 m excluding circular segment that determines chord length 10 meters. Pool depth is h = 2m. How many hectoliters of water can fit into the pool?
  12. Climb in percentage
    12_percent_stupanie The height difference between points A and B is 587 m. Calculate the percentage of route climbing if the horizontal distance places A, B is 4.8 km.
  13. Rotation
    cone_1 Right triangle with legs 14 cm and 20 cm rotate around longer leg. Calculate the volume and surface area of the formed cone.
  14. Guests
    hostia How many ways can 5 guests sit down on 6 seats standing in a row?
  15. VAT
    Tax John paid 100 Euros in store for purchase. Calculate value added tax (VAT), which paid in purchase, if the VAT rate is 20%.
  16. Birthdate
    lizatka Jane on birthday brought 30 lollipops and 24 chewing gum for their friends. How many friends has, if everyone receives the same number of lollipops and chewing gums? How much chewing gum and lollipops got any friend?
  17. Ladder
    rebrik_1 Ladder 8 m long is leaning against the wall. It foot is 1 m away from the wall. In which height ladder touch the wall?
  18. Trapezoid
    trapezoid_1 Calculate area of trapezoid ABCD with sides |AD|= 69 cm, |DC|=35 cm, |CB|=21 cm, |AB|=29 cm..
  19. Air mass
    airbaloon What is the weight of the air in a classroom with dimensions 10 m × 0 m × 2.5 m ? The air density is 1.293 kg/m3.
  20. R Trapezium
    Trapezium_example Rectangular trapezium has bases 12 and 5 and area 84 cm2. What is its perimeter?

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