Examples for 8th grade - page 23

  1. Kids
    kids How many different ways can sit 5 boys and 5 girls in line, if girls want to sit on the edge?
  2. Task
    cube_1 I have homework. The cube has an edge 11 cm long and I must find wall and body diagonal.
  3. Perpendicular
    slopeplane What is the slope of the perpendicular bisector of line segment AB if A[-9,-8] and B[-8,0]?
  4. Cable car 2
    lanovka_1 Cable car rises at an angle 39° and connects the upper and lower station with an altitude difference of 345 m. How long is the track of cable car?
  5. 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 217 gastro tickets of 2.7 € and you know that the company issuing gastro tickets get 4.4% fee of
  6. Sphere - parts
    odsek_vusek Calculate the area of a spherical cap, which is part of an area with base radius ρ = 10 cm and a height v = 2.7 cm.
  7. Salary
    platy Calculate equivalent annual salary to hourly salary $ 29. Assume a 40-hour work week.
  8. 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.
  9. 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
  10. Right triangle
    thales_2 Draw a right triangle ABC if |AB| = 5 cm |BC| = 3 cm, |AC| = 4 cm. Draw Thales circle above the hypotenuse of the triangle ABC.
  11. Acids
    acids 76% 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 94% concentration?
  12. Triangular prism
    hranol_3bokovy Calculate the surface area and volume of a triangular prism, base right triangle if a = 3 cm, b = 4 cm, c = 5 cm and height of prism h=12 cm.
  13. Rhombus base
    paral_prism Calculate the volume and surface area of prisms whose base is a rhombus with diagonals u1 = 17 cm and u2 = 10 cm. Prism height is twice base edge length.
  14. Perpendicular
    perpendicular Determine the slope of the line perpendicular to the line p: y = -10x +7.
  15. Column
    pole_phone Perpendicular pole high 6 m tall broke and its toe fell 2.8 m from the bottom of the pole. At what height above the ground pole broke?
  16. 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.
  17. Salary
    500euro Clerk got to pay 1200 Euros in banknotes of 50 and 200 Eur. Total got 9 banknotes. How many was which?
  18. Chord
    chord In a circle with radius r=11 cm is chord 4× longer than its distance from the center. What is the length of the chord?
  19. Certificate
    ucitel There is 28 students in a class. From mathematics was'nt worse mark than 2. Average mark in mathematics was 1.4643. How many students have mark 1 and how many mark 2?
  20. Segments
    segments Line segments 90 cm and 5.1 dm long we divide into equal parts which lengths in centimeters is expressed integer. How many ways can we divide?

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