Examples for 8th grade - page 38

  1. Well
    well Rope with a bucket is fixed on the shaft with the wheel. The shaft has a diameter 60 cm. How many meters will drop bucket when the wheels turn 15 times?
  2. Complementary angles
    angles_2 Two angles are complementary. If one angle measures 49°, what is the measure of the second angle?
  3. Isosceles III
    demos The base of the isosceles triangle is 24 cm area 416 cm2. Calculate the perimeter of this triangle.
  4. Plastic pipe
    pvc-trubka Calculate weight of the plastic pipe with diameter d = 60 mm and length 400 cm if the wall thickness is 6 mm and the density of plastic is 1228 kg/m3.
  5. Fertilizer
    okurky Mr. Gherkin use for fertilization 9% solution of fertilizer. 7 liters of it still left. How much water must be added to the solution to make only 5% solution?
  6. Train
    High-Speed-Train A passenger train traveled for 4 hours 136 km. 2.7 hours after its departure started fast train and caught it on 324 km. How many km/h is different its average speeds?
  7. Quadrant
    quadrants In what quadrant is a 1501° angle?
  8. Right triangle
    triangles_1 Right triangle ABC with side a = 16 and the area S = 80. Calculate the length of the remaining sides.
  9. Salary
    platy Calculate equivalent annual salary to hourly salary $ 29. Assume a 40-hour work week.
  10. Heron backlaw
    heron_math Calculate missing side in a triangle with sides 33 and 27 and area 118.3.
  11. Cylinder - basics
    cylinder Cylinder with base radius r = 37 cm and height h=74 cm. Calculate:
  12. Tiles
    100dlazdic How many tiles of 20 cm and 30 cm can build a square if we have a maximum 100 tiles?
  13. Percentage - fractions
    rubik About what percentage we must increase number 1/6 to get number 1/3?
  14. Three drivers
    gas_car Three driversdriving the same direction found that they have same amounth of gasoline. The first is enough to go 6 km, 4 km second and third 3km. Gasoline they divided so all three just drove to the nearest petrol station. How many km away was a petrol sta
  15. Reducing number
    123 Reducing the an unknown number by 28.5% we get number 243.1. Determine unknown number.
  16. Nine-gon
    9gon_1 Calculate the perimeter of a regular nonagon (9-gon) inscribed in a circle with a radius 20 cm.
  17. Mom and daughter
    family_1 Mother is 39 years old. Her daughter is 15 years. For many years will mother be four times older than the daughter?
  18. angles in quadrilateral
    4uhelnik What size have angles in quadrilateral (4-gon) if they are in a ratio of 8: 9: 10: 13?
  19. Truck
    auto In 7 hours started from town Krnov truck at speed 40 km/h. Passenger car started against it in 8 hours 30 minutes from the city of Jihlava at speed 70 km/h. Distance between this two cities is 225 km. At what time and at what distance from Krnov this two.
  20. Salt
    sol 1 t of sea water contains 25 kg of salt. How many tons of seawater must be evaporated to obtain 2 q of salt?

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.