Examples for 9th grade - page 32

  1. Bronze, tin and copper
    zvon Bronze is an alloy of tin and copper. An alloy of 10% tin and 90% copper is Gunmetal. If it contains 20% tin and 80% copper, it is bell metal. How many tons of molten bell metal and how many tons of copper is needed to make 100 tons of Gunmetal?
  2. 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).
  3. TV diagonal
    diagonal Diagonal TV is 0.56 m long, how big the television sreen is if the aspect ratio is 16:9?
  4. Circle sector
    vysec Circular sector with a central angle 10 ° has area 254 cm2. Calculate its radius r.
  5. Lathe
    sustruh Calculate the percentage of waste if the cube with 52 cm long edge is lathed to cylinder with a maximum volume.
  6. Scale
    valec_vykres Cylinder was drawn in scale 7:1. How many times is the volume of the cylinder smaller in reality?
  7. Function
    lin_functions For linear function f(x) = ax + ​​b ‬ is f(12)=118; f(15)=132. Calculate m, if f(m) = 2005 .
  8. 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?
  9. Cosine
    theta Calculate the cosine of the smallest internal angle in a right-angled triangle with cathetus 19 and 4 and with the hypotenuse 19.416.
  10. Rectangular trapezoid
    rt_licho The rectangular trapezoid ABCD is: /AB/ = /BC/ = /AC/. The length of the median is 6 cm. Calculate the circumference and area of a trapezoid.
  11. Baker
    pekar The baker makes from 10 kg of flour 12 kg dough. How much flour he need to make a 100 kg dough?
  12. Against each other
    Lotus_Esprit From two points A, B distant 45 km at the same time started two cars against each other at speeds 81 km/h and 67 km/h. How long does cars meet and what distance passes each of them?
  13. Arc
    angles Convert to arc measures (radians): 1367 ° Result write as a multiple of π
  14. 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.
  15. 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?
  16. Triangle
    star Calculate the area of ​​the triangle ABC if b = c = 20 cm, R = 21 cm (R is the circumradius).
  17. Summerjob
    pat_mat Albert, Beny, Cyril and Dan worked on summerjob. From the total revenue Albert received 2/5, Beny 1/6 , 3/10 Cyril and Dan the rest which is 324 euros. How many euros earned every one of them?
  18. Logs
    tramy The log has diameter 30 cm. What's largest beam with a rectangular cross-section can carve from it?
  19. 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
  20. Angle
    atan A straight line p given by the equation ?. Calculate the size of angle in degrees between line p and y-axis.

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