Examples for 8th grade - page 8

  1. Cube zoom
    krychle_1 How many percent we increase volume and surface of cube, if we magnify its edge by 61%.
  2. VAT
    Tax John paid 1000 Euros in store for purchase. Calculate value added tax (VAT), which paid in purchase, if the VAT rate is 20%.
  3. Rotation
    cone_1 Right triangle with legs 9 cm and 16 cm rotate around longer leg. Calculate the volume and surface area of the formed cone.
  4. Trapezoid
    trapezoid_1 Calculate area of trapezoid ABCD with sides |AD|= 33 cm, |DC|=15 cm, |CB|=19 cm, |AB|=13 cm..
  5. Quarter circular
    quarter_circle The wire that is hooked around the perimeter of quarter-circular arc has length 14π+56. Determine the radius of circle arc.
  6. Rhombus
    rhomus_circle It is given a rhombus of side length a = 11 cm. Touch points of inscribed circle divided his sides into sections a1 = 6 cm and a2 = 5 cm. Calculate the radius r of the circle and the length of the diagonals of the rhombus.
  7. Triangle
    eq_triangle Can be rectangular triangle equilateral?
  8. The cyclist
    cyclist The cyclist went from village to town. First half of journey went at 19 km/h. The second half of the journey, which mostly fell, went at 33 km/h. All journey took 67 minutes. Calculate the distance from the village to the town.
  9. Air mass
    airbaloon What is the weight of the air in a classroom with dimensions 5 m × 2 m × 3.1 m ? The air density is 1.293 kg/m3.
  10. R Trapezium
    Trapezium_example Rectangular trapezium has bases 17 and 7 and area 80 cm2. What is its perimeter?
  11. Car range
    Lupo_3L_TDI.JPG Calculate the maximum range of car, if you can spend 25 euros, price of diesel is 1.55 Eur/l and car consumption is 6.4 l/100 km.
  12. Inflation
    tsar Once upon a time, tsar owned a money printer and printed and printed. The result of printing money prices went up,in the first year 5.9 %, in the second 2.4%, in the third 5.9% and in the fourth 5.7%. Then tsar was failed in election. Calculate the av
  13. Train and car
    car_vs_train The train and the car started at a constant speed to journey. When the train travels 78 km, the car travels 64 km. How many km travels the train when the car travels 78 km?
  14. Sea water
    sea_1 Seawater contains about 7% salt. How many dm3 of distilled water we must pour into 14 dm3 of sea water to get water with 1.7% salt?
  15. Angles
    rhombus_1 Determine the interior angles of a rhombus with area 240.6 cm2 and perimeter 64 cm.
  16. Rates
    gas_meter When gas consumption, the consumer may choose one of two rates: rate A - which pays 0.35 € per 1 m3 of gas a flat monthly fee of 3.6 € (regardless of consumption) rate B - which pays 0.295 € per 1 m3 of gas a flat monthly fee of 8.3 € From what monthl
  17. Guests
    hostia How many ways can 7 guests sit down on 9 seats standing in a row?
  18. Negative percentage
    trabant In 2003, the company had a loss of 25600 Euros. Two years later he was already in profit 25200 Eur. Calculate what percentage of the company increased profits in this two years.
  19. Saving
    cars Kevin save € 4620 to buy a car. Yet it lacks save 65% of the car price. How much is the car?
  20. Cube - angles
    cube_diagonal_1 Calculate angle between the wall diagonal and cube base. Calculate the angle between the cube body diagonal and cube base.

Do you have interesting mathematical example that you can't solve it? Enter it and we can try to solve it.

To this e-mail address we will reply solution; solved examples are also published here. Please enter e-mail correctly and check whether you don't have a full mailbox.