Examples for 8th grade - page 50

  1. Cottages
    chatky The summer camp is 41 cottages. Rooms are for three and for four in them. How many of the 140 campers lives of three?
  2. Surveyor
    totalna-stanica Calculate the area of ​​what may vary rectangular, if it focused by surveyor and found the dimensions 14 x 12 m while in each of the four joint points can be position deviation 8 cm?
  3. Interest p.a.
    2dane-peniaze Calculate the value of interest in period of 1 year from the deposit 62000 CZK at 8 percent interest rate, after deducting 15 percent tax.
  4. Three workers
    3workers Three workers were rewarded CZK 7200 and the money divided by the work they have done. First worker to get twice than the second, the second three times more than the third. How much money each worker received?
  5. Two trains meet
    train From A started at 7:15 express train at speed 85 km/h to B. From B started passenger train at 8:30 in the direction to A and at speed 55 km/h. The distance A and B is 386 1/4 km. At what time and at what distance from B the two trains meet?
  6. Number
    percent What number is 24 % smaller than the number 51?
  7. Equilateral triangle v2
    eq_triangle Equilateral triangle has a perimeter 36 dm. What is its area?
  8. Arc-sector
    vzorec arc length = 17 cm area of sector = 55 cm2 arc angle = ? the radius of the sector = ?
  9. Efficiency
    engine_lap A certain device consumes 93 kW and delivers 77 kW. Find its efficiency.
  10. President
    bush_president The country has 5.9 million citizens which 2.24 million are voters. Turnout was 39.9%. President R. F. was elected from 19 candidates for president and won with 28% of votes. Calculate what percentage of the country's citizens voted R.F. as president of
  11. Fraction
    polynomial For what x expression ? equals zero?
  12. Center of gravity
    triangles_9 In the isosceles triangle ABC is the ratio of the lengths of AB and the height to AB 10:12. The arm has a length of 26 cm. If the center of gravity T of triangle ABC find area of triangle ABT.
  13. Saw
    bosh_saw Blade circular saw with a diameter 42 cm turns 825 times per minute. Expresses his cutting speed in meters per minute.
  14. Every day 7 pages
    books_9 Adelka reads the book every day 7 pages. When she reads one more page a day she will read it three days earlier. How long will Adelka read a book? How much does a book of pages have?
  15. Cube from sphere
    sphere_cube What largest surface area (in cm2) can have a cube that was cut out of a sphere with radius 22 cm?
  16. Tetrahedral prism - rhomboid base
    rhombus2_2 Calculate the area and volume tetrahedral prism that has base rhomboid shape and its dimensions are: a = 12 cm, b = 70 mm, v_a = 6 cm, v_h = 1 dm.
  17. Parachutists
    parasutism Parachutists during freefall firstly held in groups of 4, then of 6, then 9, 12 and finally of 18 members. How many parachutists jump at least should be, if at each group must all be involved.
  18. Stone
    kamen When Peter threw stone in a box of water he discovered that the water level has risen by 8 cm. The box has a cuboid shape, the bottom has dimensions of 24 cm and 14 cm, height is 48 cm. What volume has a stone?
  19. The city
    m_f In the city is 2/4 of women married to 3/4 men. What percentage of townspeople is single (not married)?
  20. Bicycles
    cyclist_11 You're the owner of the transport 's learning playground. Buy bicycles of two colors but you've got to spend accurately 120000 Kč. Blue bike costs 3600Kč and red bicycle 3200Kč.

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