Examples for 8th grade - page 31

  1. Map 2
    world_map_atlas At what scale is made map if the distance 8.2 km corresponds on the map segment 5 cm long?
  2. Revenue
    odmena Mr. Robert and Mr. Norbert get together € 1400. The revenue split in the ratio of 4:3, depending upon each work. How many got each of them?
  3. Number
    sqrt_2 Is number 5.146852 irrational?
  4. Building base
    base_of_building Excavation for the building base is 350x600x26000. Calculate its volume in m3.
  5. SAS triangle
    triangles2 The triangle has two sides long 7 and 19 and included angle 36°. Calculate area of this triangle.
  6. Addends
    1plus1 Number 839 divide into the two addends that the first was 17 greater than 60% of the second. Determine these addends.
  7. The body
    body_cubes The body on the figure consists of cubes with an edge length 6 cm. What surface has this body?
  8. Workman - shift
    favorit_skoda The worker produces 300 components per shift. How many components would be produced in 18 shift, if his performance gradually increased every shift by 3 components?
  9. Cube 6
    cubes_20 Volume of the cube is 216 cm3, calculate its surface area.
  10. Tunnels
    Mysky Mice had built an underground house consisting of chambers and tunnels: • each tunnel leading from the chamber to the chamber (none is blind) • from each chamber lead just three tunnels into three distinct chambers, • from each chamber mice can get to any
  11. Katy MO
    reporter_saved6 Kate draw triangle ABC. Middle of AB have mark as X and the center of the side AC as Y. On the side BC wants to find the point Z such that the content area of a 4gon AXZY was greatest. What part of the triangle ABC can maximally occupy 4-gon AXZY?
  12. Mother and daughter
    mom_daughter Three years ago mother was three times older than daughter. After nine years she will be only twice old. How old is mother (and daughter)?
  13. Warehouse cars
    car_6 From the warehouse started truck at speed 40km/h. After 1hour 30mins started from the same place same direction a car at speed 70 km/h. For how long and at what distance from the warehouse overtake a truck?
  14. Exam average
    vysvedcenie_2 Average of marks that have on the certificates students of 8.A class in mathematics is exactly 2.45. If we did not add 1 and 3 of sutdents Michael and Alena, who arrived a month ago, it would average exactly 2.5. Determine how many students have class 8.
  15. Suit
    oblek The suit cost 119 euros. How much cost the pants if it is 50% cheaper than the jacket.
  16. Spirit
    lieh From 55% and 80% spirit we would like to produce 0.2 kg of 60% spirit. How many of them we must use in a solution?
  17. Sprayers
    postrekovac The vineyard can be sprayed first sprayer in 5 hours and with the second in 8 hours. How long would it take if we use sprayers both at once?
  18. Chess
    sachovnica How many ways can select 4 fields on classic chess board with 64 fields, so that fields don't has the same color?
  19. VAT
    tax VAT is a tax which the state artificially betrays goods and services for final consumption. VAT in Slovakia is 20%. Calculate how much percent pay less tax residents of Liechtenstein, when VAT is only 8%.
  20. Work
    dlazba.pg First paver pave pavement for 27 hours. Second for 27 hours. Started first paver and after 4 hours, join the second. How long will they finish pavement?

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