Examples for 8th grade

  1. Parallelogram
    kosodlznik3_1 Rhomboid (parallelogram) has a longer side of 50 cm long. The size of its one height is four times the size of its second height. Calculate the length of the shorter side of this rhomboid in the centimeters.
  2. Feet to miles
    runners_6 A student runs 2640 feet. If the student runs an additional 7920 feet, how many total miles does the student run?
  3. Octagonal tank
    octagon_prism The tank has the shape of a regular octagonal prism without an upper base. The base edge has a = 3m, the side edge b = 6m. How much metal sheet is needed to build the tank? Do not think about losses or sheet thickness.
  4. KLMN trapezoid
    lich_3 The KLMN trapezoid has bases KL 40cm and MN 16cm. On the KL base is point P. The segment NP divides the trapezoid into units with the same area. What is the distance of point P from point K?
  5. Volume of ball
    ball1_5 Find the volume of a volleyball that has a radius of 4 1/2 decimeters. Use 22/7 for π
  6. The volume 2
    cubes3_11 The volume of a cube is 27 cubic meters. Find the height of the cube.
  7. Land
    12-13-5-triangle Rectangular triangular land has area 30 square meters and 12 meters long leg. How many meters of the fence do you need for fencing this land?
  8. On a farm
    sheep-500_3 On a farm, there are 90 rabbits, 700 sheep, 300 cattle and 500 pigs. What percentage of the total number of animals are rabbits?
  9. Find diagonal
    diagonal_3 Find diagonal of cuboid with length=20m width=25m height=150m
  10. Two friends
    clock-night-schr_13 Peter can do all his work himself in 6 hours. Martin can do the same work himself in 8 hours. Peter worked first and then replaced by Martin. Whole work was done in 6.5 hours. Calculate how long Peter worked before replaced by Martin.
  11. Area to volume
    two_cubes_2 If the surface area of a cube is 486, find its volume.
  12. Sugar production
    cukrrka_1 From 1 ton of beet, 150 kg of sugar is produced. To clean 1 ton of sugar 450 kg of lime is consumed. Calculate how many kgs of lime is consumed when processing 1 ton of sugar beet?
  13. Mushrooms
    hriby Fresh mushrooms contain 88% water, dried 14% water. How many kilograms of fresh mushrooms should be collected to get 3 kg of dried?
  14. Marriage sttus
    family_26 In our city, there are 3/5 of the women married to 2/3 of the men. Find what part of the population is free.
  15. The florist
    ruze_6 The florist had 200 roses in the morning. During the day, more than half sold it. From the remaining roses, it will tie the bouquet. If a bouquet of 3, 4, 5 or 6 roses are bound, one always remains. How many roses from the morning shipment sold?
  16. Cube
    cube_diagonals_3 The sum of all cube edges is 30cm. Find the surface area of the cube.
  17. Three machines
    rozvrh_1 The power of the three machines is 2: 3: 5. Two most powerful machines produce 400 parts per hour. How many components make all three machines in 3 hours?
  18. A tile
    tiles_9 A tile setter is covering 5ft by 5ft square shower wall. Each tile covers 4 5/8in by 4 5/8in square. How many rows of tile are needed to reach 5ft? How many tiles are needed to cover 5ft by 5ft square
  19. Ages 2
    time_13 A man's age is 4 times his son's age. After 5 years he will be just twice his son's age, find their ages.
  20. Chocolate
    cokolada_7 I have a box of chocolate - white, milk and dark. The ratio of white to milk with dark is 3: 4. The ratio of white and milk to dark is 17: 4. Calculate what is the ratio between white, milk, dark chocolate.

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