Examples for 8th grade - page 10

  1. Number ratio
    ratio2 Calculate two positive numbers that its ratio is 4:4 and sum was 184.
  2. Pyramid roof
    pyramid_roof 1/3 of area of ​​the roof shaped regular tetrahedral pyramid with base edge 10 m and height of 4 m is already covered with roofing. How many square meters still needs to be covered?
  3. ISO triangle
    rr Calculate the area of an isosceles triangle KLM if the length of its sides are in the ratio k:l:m = 4:4:3 and has perimeter 128 mm.
  4. Climb in percentage
    12_percent_stupanie The height difference between points A and B is 442 m. Calculate the percentage of route climbing if the horizontal distance places A, B is 6.8 km.
  5. Prism
    cuboid_2 Three cubes are glued into prism, sum of the lengths of all its edges is 259 cm. What is the length of one edge of the original cube?
  6. Profitable bank deposit 2012
    eurocoins Calculate the value of what money lose creditor with a deposit € 7700 for 4 years if the entire duration are interest 2.2% p.a. and tax on interest is 19% and annual inflation is 3.6% (Calculate what you will lose if you leave money lying idle at negative
  7. Hollow sphere
    Xmas_ball Calculate the weight of a hollow brass sphere (density 8.5 g/cm3), if the outer diameter is 10 cm and wall thickness is 3 mm.
  8. Cube
    kocka_rubik The cube weighs 47 kg. How weight is cube of the same material, if its dimensions are 3-times smaller?
  9. Equilateral triangle
    3angle_in_circle How long should be the minimum radius of the circular plate to be cut equilateral triangle with side 7 mm from it?
  10. Diagonals of the rhombus
    diagonals_rhombus Calculate height of rhombus whose diagonals are 15 cm and 5 cm.
  11. Hexagon A
    hexagon Calculate area of regular hexagon inscribed in circle with radius r=7 m.
  12. Tetrahedral pyramid
    jehlan_1 Calculate the volume and surface area of a regular tetrahedral pyramid, its height is $b cm and the length of the edges of the base is 7 cm.
  13. Bicycle wheel
    bicycle Bicycle wheel has a diameter of 60 cm. Approximately how many times the wheel rotates at 3.7 km long trip?
  14. Tower
    cone_roof How many m2 of copper plate should be to replace roof of the tower conical shape with diameter 13 m and the angle at the vertex of the axial section is 150°?
  15. Right isosceles
    right_isosceles_triangle Calculate area of the isosceles right triangle which perimeter is 35 cm.
  16. Road
    cesta Between cities A and B is route 3 km long of rise average 4‰. Calculate the height difference of cities A and B.
  17. Triangular prism
    TriangularPrism Plane passing through the edge AB and the center of segmet CC' of regular triangular prism ABCA'B'C', has angle with base 50 degrees, |AB| = 5 cm. Calculate the volume of the prism.
  18. Team
    football The football team has 11 players. Their average age is 21 years. During the match due to injury, one player withdraws and the average age of the team is 20. How old was injured player?
  19. Tourists
    hiking From the cottage started first group of tourists at 10:00 AM at speed 4 km/h. The second started after them 39 minutes later at speed 6 km/h. How long and how many kilometers from the cottage will catch the first group?
  20. 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?

Do you have interesting mathematical example that you can't solve it? Enter it and we can try to solve it.



To this e-mail address we will reply solution; solved examples are also published here. Please enter e-mail correctly and check whether you don't have a full mailbox.