Examples for 8th grade - page 21

  1. Height difference
    road What height difference overcome if we pass road 1 km long with a pitch21 per mille?
  2. Pizza master
    pizza_3 Master says that he can splits pizza to 16 parts by five equals straight cuts. Is it possible?
  3. Pizza
    pizza_1 A school survey found that 9 out of 16 students like pizza. If 5 students are chosen at random, what is the probability that all 5 students like pizza?
  4. Distance
    distance Calculate distance between two points Z[7; -9] and U[-10; -8].
  5. Cuboid
    cuboid_3 Cuboid ABCDEFGH with 10 cm height has a base edge length 6 cm and 8 cm. Determine angle between body diagonal and the base plane (round to degrees).
  6. Icerink
    klzisko-korcule Rectangular rink with dimensions of 79.5 m and 529 dm must be covered with a layer of ice 4.5 cm thick. How many liters of water is necessary for the formation of ice when the volume of ice is 10.9% greater than the volume of water.
  7. Lunch for free
    Gastrolistky Gastro ticket are "free" and therefore they should be retained. This think many employees in Slovakia. Calculate how much money employee yearly earn if he get 217 gastro tickets of 2.7 € and you know that the company issuing gastro tickets get 4.4% fee of
  8. Tiles
    tiles_1 The room has dimensions 12 m and 5.6 m. Determine the number of square tiles and their largest possible size to cover them room's floor.
  9. Trains for people
    757_rusen It is said that the train is synonymous to delay. Calculate the average speed of travel by train long 50 km, with regular train leave at 6:05 and arrive at 7:20, but train is late and has departure at 9:52 and arrive at 11:05.
  10. Triangle KLB
    rovnostranny_trojuholnik It is given equilateral triangle ABC. From point L which is the midpoint of the side BC of the triangle it is drwn perpendicular to the side AB. Intersection of perpendicular and the side AB is point K. How many % of the area of the triangle ABC is area o
  11. Tank
    barrel_1 In the middle of a cylindrical tank with a bottom diameter 350 cm is standing rod which is 31 cm above the water surface. If we bank rod its end reach surface of the water just by the tank wall. How deep is the tank?
  12. Water container
    water_1 Container with water weighs 1.48 kg. When we cast 75% of water container of water weight 0.73 kg. How heavy is an empty container?
  13. Circumferential angle
    uhly Vertices of the triangle ΔABC lies on circle and divided it into arcs in the ratio 5:5:3. Determine the size of the angles of the triangle ΔABC.
  14. Kids
    kids How many different ways can sit 5 boys and 5 girls in line, if girls want to sit on the edge?
  15. Salary
    platy Calculate equivalent annual salary to hourly salary $ 29. Assume a 40-hour work week.
  16. Map - climb
    Lanovka_na_skalnate_pleso On the map of High Tatras in scale 1:25000 are cable car stations in the Tatranska Lomnica and in the Skalnate Pleso with distance 156 mm. Altitude of this stations are 944 m and 1755 m. What is average angle of climb of this cable car track?
  17. Newton's task
    cow Grass grows in the meadow equally fast and evenly. It is known that 58 cows graze meadow for 30 days and 80 cows by 19 days. How many cows graze meadow for 6 days?
  18. ISO trapezium
    trapezium_2 Calculate area of isosceles trapezoid with base 53 long, leg 43 long and with the angle between the base and leg 70 degrees.
  19. Column
    pole_phone Perpendicular pole high 6 m tall broke and its toe fell 2.8 m from the bottom of the pole. At what height above the ground pole broke?
  20. Water inlets
    pipe Inlet valve with a flow rate of 12 liters per second is filled tank for 72 minutes. How long take to fill full tank if we open one more such valve half an hour after?

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