Examples for 8th grade - page 63

  1. Isosceles right triangle
    IsoscelesRightTriangle Contents of an isosceles right triangle is 18 dm2. Calculate the length of its base.
  2. Chord 2
    circle_ Point A has distance 13 cm from the center of the circle with radius r = 5 cm. Calculate the length of the chord connecting the points T1 and T2 of contact of tangents led from point A to the circle.
  3. Wheel
    bicycle_1 Diameter of motocycle wheel is 52 cm. How many times rotates wheel on roand long 2 km?
  4. 3 years
    ekonomicky-rast The company has increased the number of employees. In year 2005 compared to 2004 13% more, in 2006 18% more against the previous year, in year 2007 20% more compared to 2006. How many % increase in the number of employees in 3 years?
  5. Tripled square
    squares4_1 If you tripled the length of the sides of the square ABCD you increases its content by 200 cm2. How long is the side of the square ABCD?
  6. Probability - tickets
    zreby What is the probability when you have 25 tickets in 5000 that you not wins the first (one) prize?
  7. Runners circle
    runners Pepa circles the track in 36 seconds. Kamil in 42 seconds. They started together. How many seconds will meet again at the start?
  8. Pyramid 4sides
    pyramid_2 Calculate the volume and the surface of a regular quadrangular pyramid when the edge of the base is 4 cm long and the height of the pyramid is 7 cm.
  9. Ethnicity
    indian Share of ethnicity XY is 26%, which is 1/9 more than in the prewar period. What was the share of that ethnicity in the pre-war period?
  10. Chord 5
    kruhy It is given circle k / S; 5 cm /. Its chord MN is 3 cm away from the center of the circle . Calculate its length.
  11. Right triangle
    rt_triangle It is given a right triangle angle alpha of 90 degrees beta angle of 55 degrees c = 10 cm use Pythagorean theorem to calculate sides a and b
  12. Percent chaining
    meter_1 Calculate 20% from 70% from 80 km
  13. Prism
    hranol_3bokovy_1 Find the volume and surface area of prism with base of an equilateral triangle with side 7 dm long and the body height of 1.5 m.
  14. Farm2
    pecene_kure The farm bred turkeys, geese, hens and chickens. Everything is 400. Turkeys and geese a hen are 150. No hen has more than one chicken, but some hens has no chick. Half of them is also a quarter of the chickens. When the turkey subtracting 15, we get 75. Ho
  15. 4 pipes
    roury The tank flows out by 4 pipes in 6 hours 120 hl water. How much water flows out of 5 pipes of the same diameter in 14 hours?
  16. Two rooms
    clean_1 Woman cleans the room in 30 minutes a man in 90 minutes. How long will take they clean two rooms?
  17. Tiles
    wall-tiles-img-5 How many square tiles with the content 121 cm2 has to be ordered for the paving of the square room with a side length of 2.75 meters?
  18. Algebrogram
    plus_2 Solve algebrogram: mama+anna=vari How many solutions are?
  19. Coal
    coal If the daily consumption of 1.6 tons of coal, it is sufficient to supply the boiler for 42 days. How long is sufficient to supply when will burn only 1.2 tons of coal a day ?
  20. Double percent
    percents What is 80% of 60% of 2800?

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