Examples for 9th grade - page 33

  1. Maple
    tree_javor Maple peak is visible from a distance 4 m from the trunk from a height of 1.7 m at angle 50°. Determine the height of the maple.
  2. Digits
    numbers2_18 How many natural numbers greater than 4000 which are formed from the numbers 0,1,3,7,9 with the figures not repeated, B) How many will the number of natural numbers less than 4000 and the numbers can be repeated?
  3. Cone container
    kuzel_1 Rotary cone-shaped container has a volume 1000 cubic cm and a height 12 cm. Calculate how much metal we need for making this package.
  4. Reflector
    lamp Circular reflector throws light cone with a vertex angle 60° and is on 22 m height tower. The axis of the light beam has with the axis of the tower angle 24°. What is the maximum length of the illuminated horizontal plane?
  5. Trigonometry
    sinus Is true equality? ?
  6. Math logic
    children_7 There are 20 children in the group, each two children have a different name. Alena and John are among them. How many ways can we choose 8 children to be among the selected A) was John B) was John and Alena C) at least one was Alena, John D) maximum one w
  7. Railways - golden parachutes
    pavel-kravec_kdh As often happens in Slovakia habit, the state's financial institution which takes from poverty and gorilas give. A hardworking punishing taxes. Let's look at a short work of director Railway Company ZSSK - Mgr . P. K. : 18 months 'work' as director r
  8. Euclid theorems
    euklidova_veta_trojuhelnik_nakres Calculate the sides of a right triangle if leg a = 6 cm and a section of the hypotenuse, which is located adjacent the second leg b is 5cm.
  9. Brass tube
    Ms_trubka The outer perimeter of brass tube (ρ = 8.5 g/cm3) is 51 cm. Its mass is 5 kg, length 56 cm. What is the pipe wall thickness?
  10. Tournament
    turnaj Determine how many ways can be chosen four representatives from 27 students to school tournament.
  11. Rectangular triangles
    r_triangles The lengths of corresponding sides of two rectangular triangles are in the ratio 2:5. At what ratio are medians relevant to hypotenuse these right triangles? At what ratio are the contents of these triangles? Smaller rectangular triangle has legs 6 and 8 c
  12. Angle
    atan A straight line p given by the equation ?. Calculate the size of angle in degrees between line p and y-axis.
  13. Words
    words How many 3 letter "words" are possible using 18 letters of the alphabet? a) n - without repetition b) m - with repetition
  14. Medals
    medails In how many ways can be divided gold, silver and bronze medal among 18 contestant?
  15. Two cars
    car_racing Car A1 goes at average speed of 133 km/h and the second car A2 goes at 128 km/h. How many second will it take car A1 to circulate car A2? Assume that both cars are 4.7 meters long and the safety gap between cars is 2.7 meters.
  16. Sphere fall
    sphere How many percent fall volume of sphere if diameter fall 5×?
  17. Raffle
    tombola How many raffle tickets must be purchased by Peter in raffle with issued 200 tickets if he wants to be sure win at least 3 price? In the raffle draws 30 prices.
  18. 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).
  19. Pipeline
    pipeline How much percent has changed (reduced) area of pipe cross-section, if circular shape changed to square with same perimeter?
  20. The camp
    diary At the end of the camp a 9 friends exchanged addresses. Any friend gave remaining 8 friends his card. How many addresses they exchanged?

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