Examples for 8th grade - page 15

  1. Train
    High-Speed-Train A passenger train traveled for 4 hours 136 km. 2.7 hours after its departure started fast train and caught it on 324 km. How many km/h is different its average speeds?
  2. Wire D
    semicircle_1 Wire length 5 m is bent so that it forms a semicircle circuit (including the diameter). Determine the radius of the semicircle.
  3. KLMN
    trapezium In the trapezoid KLMN is given this informations: 1. segments KL and MN are parallel 2. segments KL and KM has same length 3. segments KN, NM and ML has same length. Determine the size of the angle KMN.
  4. Lead cube
    pb_cube Calculate the edge of the cube made ​​from lead, which weighs 11 kg. The density of lead is 11341 kg/m3.
  5. Parquet floor
    Parkett Three workers laid parquet floor for 1.957 hour. The first one would do this work alone 5 hours, the second in 9 hours. For how many hours would fulfill this work the third worker, if he worked alone?
  6. Height
    thales_law Is right that in any right triangle height is less or equal half of the hypotenuse?
  7. Rhombus
    rhombus2 Internal angles of rhombus is in ratio 3:6. How many times is the shorter diagonal longer than side of rhombus?
  8. Triangle in circle
    triangle_in_circle Vertices of the triangle ABC lies on a circle with radius 6 so that it is divided into three parts in the ratio 3:2:5. Calculate the circumference of the triangle ABC.
  9. Cylinder - h
    cylinder_2 Cylinder volume is 129 cm3. Base radius is 3 cm. Calculate the height of the cylinder.
  10. Wood in the forest
    drevo The amount of wood in the forest was estimated at 24000 m3. How much wood will be in forest after 3 years if the annual growth of wood is 3% each year and logging 360 m3 each year?
  11. Slope
    slope What is the slope of a line with an inclination 52°?
  12. Stock market
    money_1 Simon one day decided to invest € 88000 to the stock market. After six months he invested July 5 stock markets fell by 56%. Fortunately for Simon from July 5 5 to October 5 his shares have risen by 39%. Simon is then: ?
  13. Prism
    prism-square The lenght, width and height of a right prism are 18, 14 and 9 respectively. What is the lenght of the longest segment whose endpoints are vertices of the prism?
  14. Cyclists
    cyclist_3 Cyclist who rides at an average speed 17 km/h travels trip distance 14 min before the cyclist who rides at an average speed 15 km/h. What is the length of this cyclist trip(distance in km)?
  15. Rhombus 2
    koso Calculate the area of rhombus which has a height v=48 mm and shorter diagonal u = 60 mm long.
  16. Division
    bonbons Three siblings Helena, Oliver and George split the bag with candies on merit in the ratio 1:6:3. How many candies should each get if in bag were 210?
  17. Magnification of the square
    square If we increase the square side, increase the content of the 42 %. About what percentage was increased his sides?
  18. Crossroads
    crossroad The rectangular crossroads comes passenger car and an ambulance, the ambulance left. Passenger car is at 45 km/h and ambulance 58 km/h. Calculate such a relative speed of the ambulance moves to the car.
  19. Rotating cone II
    cone Calculate area of surface of rotating cone with base radius r=7 cm and height h=17 cm.
  20. Playing cards
    playing_cards How many possible ways are to shuffle 7 playing cards?

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