Examples for 8th grade - page 42

  1. Diameter
    circles2_1 What is the inside diameter of the cylinder container and if half a liter of water reaches a height 15 cm?
  2. Tank No 8
    tank1 Tank is filled by one inlet valve with a flow rate of 12 liters per second in 72 minutes. How long take the tank to fill, if we open half an hour after one more inlet?
  3. Garden pool
    basen_1 Mr. Novak fill garden pool (cylinder; diameter of 200 cm) with 31.4 hl of water. What is the depth of the pool when the water level is 10 cm below the upper edge of the pool?
  4. Median
    medians.JPG In triangle ABC is given side a=10 cm and median ta= 13 cm and angle gamma 90°. Calculate length of the median tb.
  5. The dam
    prehrada-orlik The water reservoir is filled with first tributary for 25 hours second tributary for 35 hours. Some time were both inlets open, then a second tributary closed and the tank was filled in four hours. What time water flowed from both tributaries? (Expressed i
  6. Roots
    square_roor Calculate the square root of these numbers:
  7. Painting rooms
    palma_1 If Dano paint three hours daily given work he complete in 7.5 days. How many hours a day would have to work to finish the job 1.5 days earlier?
  8. Inscribed triangle
    obluk To a circle is inscribed triangle so that the it's vertexes divide circle into 3 arcs. The length of the arcs are in the ratio 2:3:7. Determine the interior angles of a triangle.
  9. Slope
    lines.JPG Calculate the slope of a line that intersects points (38,-23) and (-93,5).
  10. Slovak broad track
    sirokorozchodna Once upon a time, we learned in school that the Russians have "wider" tracks than our, because they have less tolerable ground. In truth, decide olny area of sleepers, no track gauge. Calculate how many millimeters, our track 1435 mm different from the R
  11. Triangle
    red_triangle For how many integer values of x can 8, 11 and x be the lengths of the sides of triangle?
  12. Mine
    minetower Wheel in traction tower has a diameter 5 m. How many meters will perform an elevator cabin if wheel rotates in the same direction 10 times?
  13. Lamp cone
    lampa Calculate the surface of a lamp shade shaped of a rotary truncated cone with base diameter 32 cm and 12 cm and height 24 cm.
  14. Water pool
    basen_2 Pool with volume 990hl completely filled, if water flows by one tap 8 hours and by second tap 6 hours. First tap give 10hl more than second per hour. How many hl flows in each of them in an hour?
  15. Annulus
    medzikruzie.JPG Two concentric circles form an annulus of width 10 cm. The radius of the smaller circle is 20 cm. Calculate the content area of annulus.
  16. Right triangle
    triangles_1 Right triangle ABC with side a = 16 and the area S = 80. Calculate the length of the remaining sides.
  17. Tree
    strom How tall is the tree that observed in the visual angle of 52°? If I stand 5 m from the tree and eyes are two meters above the ground.
  18. Concentric circles
    chord_2 In the circle with diameter 17 cm is constructed chord 12 cm long. Calculate the radius of a concentric circle that touches this chord.
  19. 6 regular polygon
    hexagon_2 It is given 6 side regular polygon whose side is 5 cm. Calculate its content area. Compare how many more cm2 (square centimeters) has a circle in which is inscribed the 6-gon.
  20. Two wine
    wines In 2:1 mix wine solution cost 4.1 USD. In 1:2 mix wine solution cost 4.5 USD. How much cost liter of each wine?

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