Examples for 9th grade - page 31

  1. Sphere fall
    sphere How many percent fall volume of sphere if diameter fall 5×?
  2. Permill
    permille How many permill is 1931 from 166456?
  3. Clock
    timer What distance will pass end of 8 cm long hour hand for 15 minutes?
  4. Diamond
    cerveny_kosoctverec Side length of diamond is 35 cm and the length of the diagonal is 56 cm. Calculate the height and length of the second diagonal.
  5. Pipeline
    pipeline How much percent has changed (reduced) area of pipe cross-section, if circular shape changed to square with same perimeter?
  6. Earth's diameter
    om5960-v2 The Earth's diameter on the equator is approximately 12750 km. How long does the Gripen flyover the Earth above the equator at 10 km if it is at an average speed of 1500 km / h?
  7. Water tank 2
    tank_1 Water tank cuboid is 12 meters long and 6.5 meters wide and 1.2 meters high. How many hectoliters are in the tank when it is filled to 71%?
  8. Peleton
    tdf6 Cycling race was run at an average speed of 33 km/h. One cyclist lost with defect 6 minutes. How long and how far he must go at speed 38 km/h to catch peleton again?
  9. Prism - box
    cuboids_1 The base of prism is a rectangle with a side of 7.5 cm and 12.5 cm diagonal. The volume of the prism is V = 0.9 dm3. Calculate the surface of the prism.
  10. Ray
    luc-slnka Light ray loses 1/19 of brightness passing through glass plate. What is the brightness of the ray after passing through 3 identical plates?
  11. Unknown integer
    cross Find the smallest integer that: divided by 2, the remainder is 1 divided by 3 the remainder is 2, divided by 4 remainder is 3, ... divided by eight reminder is 7, by 9 reminder is 8.
  12. Workman - shift
    favorit_skoda The worker produces 300 components per shift. How many components would be produced in 18 shift, if his performance gradually increased every shift by 3 components?
  13. 3sides prism
    prism_3 The base of vertical prism is an isosceles triangle whose base is 10 cm and the arm is 13 cm long. Prism height is three times the height of base triangle. Calculate the surface area of the prism.
  14. Circles
    pyt_theorem In the circle with a radius 7.5 cm are constructed two parallel chord whose lengths are 9 cm and 12 cm. Calculate the distance of these chords (if there are two possible solutions write both).
  15. Scale
    valec_vykres Cylinder was drawn in scale 7:1. How many times is the volume of the cylinder smaller in reality?
  16. Function
    lin_functions For linear function f(x) = ax + ​​b ‬ is f(12)=118; f(15)=132. Calculate m, if f(m) = 2005 .
  17. TV diagonal
    diagonal Diagonal TV is 0.56 m long, how big the television sreen is if the aspect ratio is 16:9?
  18. Sales off
    sweater If a sweater sells for $ 12 after a 25% markdown, what was its original price?
  19. Lathe
    sustruh Calculate the percentage of waste if the cube with 52 cm long edge is lathed to cylinder with a maximum volume.
  20. Rectangle diagonals
    rectangle_diagonals_1 It is given rectangle with area 24 cm2 a circumference 20 cm. The length of one side is 2 cm larger than length of second side. Calculate the length of the diagonal. Length and width are yet expressed in natural numbers.

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.