Examples for 8th grade - page 12

  1. Gasholder
    gas_holder The gasholder has spherical shape with a diameter 23 m. How many m3 can hold in?
  2. Motion problem
    dragway From Bratislavy to Martina go car at speed 83 km/h. From Martina to Bratislavy go another car at speed 62 km/h. How many minutes before the meeting will be cars 21 km away?
  3. Rhombus
    rhombus Calculate the perimeter and area of ​​rhombus whose diagonals are 15 cm and 27 cm long.
  4. Unknown x
    UnknownX If we add to unknown number 72, then divide by 2 and then subtract 29, we get back an unknown number. What is this unknown number?
  5. 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?
  6. Ice cream
    zmrzlina Annie likes much ice cream. In the shop are six kinds of ice cream. In how many ways she can buy ice cream to three scoop if each have a different flavor mound and the order of scoops doesn't matter?
  7. Nuts
    nuts How many we must have at least nuts if we can equally divide it to 10 children, 14 children or 19 children and any nut left?
  8. Rhombus
    rhomus_circle It is given a rhombus of side length a = 11 cm. Touch points of inscribed circle divided his sides into sections a1 = 6 cm and a2 = 5 cm. Calculate the radius r of the circle and the length of the diagonals of the rhombus.
  9. Metals
    metals_2 In the Hockey World Cup play eight teams, determine how many ways can they win gold, silver and bronze medals.
  10. Solutions
    bilde How much 60% solution and how much 35% solution is needed to create 100 l of 40% solution?
  11. Cosine
    cosine The point (21, 20) is on the terminal side of angle θ. cos θ = ?
  12. Ladder
    studna 7.4 meters long ladder is leaning against the wall of the well and its lower end is 1.1 meters from this wall. How high from the bottom of a well is the top edge of the ladder?
  13. Cyclist
    1cyclist Cyclist goes uphill 1 km for 6.3 minutes and downhill minutes for 2.1 minutes, both applied to the pedals same force. How long he pass 1 km by plane?
  14. Class
    children_2 In a class are 32 pupils. Of these are 8 boys. What percentage of girls are in the class?
  15. 5 pumps
    pump Five pump to pump 3 hours 1600 hl of water. How long pumped same amount of water 4 pumps?
  16. Spherical cap
    kulova_usec From the sphere of radius 12 was truncated spherical cap. Its height is 4. What part of the volume is spherical cap from whole sphere?
  17. Rectangles
    rectangles How many rectangles with area 2832 cm2 whose sides is natural numbers are?
  18. Alcohol
    no_alcohol How many 46% alcohol we need to pour into 3 liters 63% alcohol to get p3% of the alcohol? How many 52% alcohol we get?
  19. Sea water
    sea Mixing 68 kg of sea water with 73 kg rainwater is created water containing 3% salt. How many percent sea water contains salt?
  20. Percent chaining
    meter_1 Calculate 20% from 70% from 80 km

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