Examples for 8th grade - page 27

  1. Rising price
    book The book first become more expensive by 5 euros. New price was later increased by 13%. After the second price increase book cost 47 euros. What was the original price of the book?
  2. Percentages
    percent2 Expressed as a percentage:
  3. Bakery
    bread_1 How heavy must prepare bread at a bakery if lose during baking 14% of water and after baking must have 1.6 kg? (Calculate to the nearest gram)
  4. Slope
    slope What is the slope of the line defined by the equation -4x -2y = -7 ?
  5. Cube in a sphere
    cube_in_sphere The cube is inscribed in a sphere with volume 6598 cm3. Determine the length of the edges of a cube.
  6. Steps
    square_diagonal_1 How many steps you save if you go square estate for diagonal (crosswise), rather than circumvent on the two sides of its perimeter with 298 steps.
  7. Diamond
    rhombus2_2 Determine the side of diamond if its content is S = 500 cm2 and one diagonal u2 = 46 cm.
  8. Circle arc
    pizza Circle segment has a circumference of 13.26 mm and 252.03 mm2 area. Calculate the radius of the circle and size of central angle.
  9. Cacao
    chocholate_2 Cacao contains 34% filling. How many grams of filling are in 130 g cacao.
  10. Smallest internal angle
    angles_3 Calculate what size has the smallest internal angle of the triangle if values of angles α:β:γ = 3:4:8
  11. Container
    canister First day got off 1/4 water from full container, second day 1/5 of the remaining water. How many percent remain container filled?
  12. Thales
    circles_1 Calculate the length of the Thales' circle described to right triangle with hypotenuse 44 cm.
  13. R Trapezium
    Trapezium_example Rectangular trapezium has bases 17 and 7 and area 80 cm2. What is its perimeter?
  14. Cuboid
    cuboid_1 The cuboid has a surface area 8710 cm2, the length of its edges are in the ratio 3:2:1. Calculate the volume of the cuboid.
  15. Work
    dlazba.pg First paver pave pavement for 33 hours. Second for 24 hours. Started first paver and after 5 hours, join the second. How long will they finish pavement?
  16. Vinegar
    vinegar We must dilute 80 liters of 7.6% aqueous vinegar to 4.2% one. How much water is necessary to add?
  17. Barrel with liquid
    barrel Barrel with grain weight 263 kg. When it shed 43% of grain, ha weight 170 kg. What is the weight of empty barrel?
  18. Triangle angles
    triangles_2 The angles α, β, γ in triangle ABC are in the ratio 10:5:6. Calculate size of angles.
  19. Apples in baskets
    basket Determine how many apples are in baskets when in the first basket are 4 apples, and in any other is 29 apples more than the previous, and we have eight baskets.
  20. Average height
    vyska In a class are 34 students. The average height of students is 165 cm. What will be the average height of students in the classroom when two pupils tall 176 cm and 170 cm moved from this school/class?

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