Examples for 8th grade - page 13

  1. Climb
    scenic_road Road has climbing 1:23. How big is a angle corresponds to this climbing?
  2. Sale
    sale_percent If the product twice price cut by 20%, what percentage was price cut in total?
  3. Motion
    bus_1 From two different locations distant 104 km started against car and bus. The car started at 5:30 with average speed 58 km/h. Bus started at 6:40 with average speed 79 km/h. When they meet? How many kilometers went the bus?
  4. OK circle
    circles2 Calculate the radius (circumradius) of the circle described right triangle with hypotenuse long 17 and one cathetus long 1.
  5. Speed of Slovakian trains
    zssk_train Rudolf decided to take the train from the station 'Nová Baňa' to 'Gelnica'. In the train timetables found train R 371 Horehronec : km0Břeclav os.n.05:268Lanžhot05:3205:3214Brodské05:3705:3818Kúty05:4205:4344Malacky05:5906:0082Bratislava hl.st.06:2606:37
  6. Inheritance
    Cross After death father (♱ 53) remained mother (his wife) and its 5 children. Inheritance by law is that in first mother will automatically get half of the property and other one half inherite by heirs witch are mother and her 5 children by same share. Cal
  7. 2x cone
    truncated_cone_2 Circular cone height 60 cm was cut plane parallel with base. Volume of these two small cones is the same. Calculate the height of the smaller cone.
  8. Rectangles
    rectangles How many rectangles with area 2832 cm2 whose sides is natural numbers are?
  9. Solidarity
    salt Imagine a word solidarity means that salt donation to the needy, who have neither the salt. If we take word solidarity has word base salt + gift (only in Slovakian language). Calculate how many kilos of salt sympathetic citizen "gives" government a year i
  10. Trapezoid
    rectangular_trapezoid Are diagonals in a rectangular trapezoid perpendicular and bisect the angles?
  11. Vinegar
    vinegar We must dilute 80 liters of 7.6% aqueous vinegar to 4.2% one. How much water is necessary to add?
  12. Circle section
    circle_segment Equilateral triangle with side 50 is inscribed circle section whose center is in one of the vertices of the triangle and the arc touches the opposite side. Calculate: a) the length of the arc b) the ratio betewwn the circumference to the circle sector.
  13. Circle and angle
    arc What is the length of the arc of a circle with radius r = 138 cm with cental angle 2.07 rad?
  14. Cone
    truncated_cone_1 Circular cone with height h = 11 dm and base radius r = 4 dm slice plane parallel to the base. Calculate distance of the cone vertex from this plane, if solids have the same volume.
  15. Two doctors
    dr_cvach Doctor A will determine the correct diagnosis with a probability 80% and doctor B with a probability 72%. Calculate probability of correct diagnosis if patient is diagnosed by both doctors.
  16. Plumber
    klempir Plumber had to cut the metal strip with dimensions 380 cm and 60 cm to the largest squares so that no waste. Calculate the length of the sides of a square. How many squares cut it?
  17. Sequence
    arithmetic_seq In the arithmetic sequence is a1=-9, d=4. Which member is equal to the number 147?
  18. Required reserves
    ecb-printing-money_1 Calculate what is the minimum amount of money that bank must hold in cash from your deposit 2100 Eur. How much money is ideally created in the banking system from your deposit if the level of minimum reserve requirement is 2.01%? Consider fractional re
  19. Balls
    balls_1 Ping pong balls have a diameter of approximately 3 cm. They are sold in boxes of 3 pieces: each box has the shape of a cuboid with a square base. The balls touch the walls of the box. Calculate what portion of the internal volume of the box is filled wit
  20. Pillar
    sliced_pyramid Calculate volume of pillar shape of a regular tetrahedral truncated pyramid, if his square have sides a = 13, b = 21 and height is h = 33.

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