Examples for 8th grade - page 23

  1. Pine wood
    dre-borovica From a trunk of pine 6m long and 35 cm in diameter with a carved beam with a cross-section in the shape of a square so that the square had the greatest content area. Calculate the length of the sides of a square. Calculate the volume in cubic meters of lum
  2. Iron sphere
    sphere_1 Iron sphere has weight 100 kg and density ρ = 7600 kg/m3. Calculate the volume, surface and diameter of the sphere.
  3. Rhombus base
    paral_prism Calculate the volume and surface area of prisms whose base is a rhombus with diagonals u1 = 14 cm and u2 = 15 cm. Prism height is twice base edge length.
  4. Height
    equilateral_triangle Calculate height of the equilateral triangle if its perimeter is 8?
  5. Sphere - parts
    odsek_vusek Calculate the area of a spherical cap, which is part of an area with base radius ρ = 9 cm and a height v = 3.1 cm.
  6. Certificate
    ucitel There is 31 students in a class. From mathematics was'nt worse mark than 2. Average mark in mathematics was 2. How many students have mark 1 and how many mark 2?
  7. Task
    cube_1 I have homework. The cube has an edge 7 cm long and I must find wall and body diagonal.
  8. Chord
    chord In a circle with radius r=70 cm is chord 10× longer than its distance from the center. What is the length of the chord?
  9. Cable car 2
    lanovka_1 Cable car rises at an angle 41° and connects the upper and lower station with an altitude difference of 1175 m. How long is the track of cable car?
  10. The car
    cars_4 The car has traveled the distance between A and B for four hour. If we increased the average by 17 km/h the car travel this distance an hour earlier. Determine the initial speed of the car and the distance between A and B.
  11. Perpendicular
    perpendicular Determine the slope of the line perpendicular to the line p: y = -x +4.
  12. Salary
    platy Calculate equivalent annual salary to hourly salary $ 19. Assume a 42-hour work week.
  13. Equilateral cylinder
    3d Equilateral cylinder (height = base diameter; h = 2r) has a volume of V = 199 cm3 . Calculate the surface area of the cylinder.
  14. Lunch for free
    Gastrolistky Gastro ticket are "free" and therefore they should be retained. This think many employees in Slovakia. Calculate how much money employee yearly earn if he get 201 gastro tickets of 2.8 € and you know that the company issuing gastro tickets get 4.9% fee of
  15. Acids
    acids 70% acid was make from same acid of two different concentrations. Amount weaker acid to the stronger acid is in ratio 2:1. What was the concentration of the weaker acid, if stronger had 91% concentration?
  16. Horizontal Cylindrical Segment
    cylinder_horiz How much fuel is in the tank of horizontal cylindrical segment with a length 10m, width of level 1 meter and level is 0.2 meters below the upper side of the tank?
  17. Column
    pole_phone Perpendicular pole high 8 m tall broke and its toe fell 2.7 m from the bottom of the pole. At what height above the ground pole broke?
  18. Rectangle
    obdelnik_1 The length of the rectangle are in the ratio 5:12 and the circumference is 238 cm. Calculate the length of the diagonal and area of rectangle.
  19. Vintner
    wine How high can vintner fill keg with crushed red grapes if these grapes occupy a volume of 20 percent? Keg is cylindrical with a diameter of the base 1 m and a volume 9.42 hl. Start from the premise that says that fermentation will fill the keg (the number.
  20. Property
    pozemok The length of the rectangle-shaped property is 8 meters less than three times of the width. If we increase the width 5% of a length and lendth reduce by 14% of the width it will increase the property perimeter by 13 meters. How much will the property cost

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