Examples for 8th grade - page 77

  1. Four ropes
    vysilac TV transmitter is anchored at a height of 44 meters by four ropes. Each rope is attached at a distance of 55 meters from the heel of the TV transmitter. Calculate how many meters of rope were used in the construction of the transmitter. At each attachment.
  2. Plum
    plumbs_1 On the platter are plum. How many were there if its have to be able to share equally among 8,10 and 12 children?
  3. Class 9A
    boy On the final certificate have one quarter of the class 9A mark "C" of mathematics, seventh mark "C" from the Czech language and two students failed in chemistry. How many students attend class 9A?
  4. Sugar 9
    cukr_6 150 kg of sugar beet yields 24 kg of sugar. From how many tons of sugar beet can be obtained three tons of sugar?
  5. Resistance
    bulb_1 Determine the resistance of the bulb with current 200 mA and is in regular lamp (230V).
  6. Trees - orchard
    jablone_2 The 3/5 trees are apple trees and 1/3 of the trees are cherries. The remaining 5 trees are pear trees. How many trees are in the orchard.
  7. Sale off 2
    sale A pair of of blues jeans went on sale. After a 30% reduction the pants cost $35. How much did the jeans cost before the price reduction?
  8. Family
    sediny Mom is 39 years old. Karl is eight years and Paul 4 years. For many years mother would old just like two children together?
  9. Cruise liner
    parnik_1 Cruise liner runs along the river between points A and B. The journey downstream takes 40 minutes 1 hour upriver. The flow rate of the river is 3 km/h. What is the speed of cruise liner?
  10. Cableway
    cable-car Cableway has a length of 1800 m. The horizontal distance between the upper and lower cable car station is 1600 m. Calculate how much meters altitude is higher upper station than the base station.
  11. Image scale
    mazanina The actual image dimensions are 60 cm x 80cm and has a reduced size 3 cm x 4 cm. At what scale the image was reduced?
  12. TVs
    tv Production of television sets increased from 3,500 units to 4,200 units. Calculate the percentage of production increase.
  13. Family parcels
    map_4 In father will he divided the land so that the older son had three bigger part than younger son. Later elder son gave 2.5 ha field to younger and they had both the same. Determine the area of family parcel.
  14. Diagonals of diamond
    kosostvorec_4 Find the area and circumference of the diamond ABCD with 15m and 11m diagonals.
  15. Pyramid Z8–I–6
    pyramida_mo Each brick of pyramid contains one number. Whenever possible, the number in each brick is lowest common multiple of two numbers of bricks lying directly above it. That number may be in the lowest brick? Determine all possibilities.
  16. Shell of cylinder
    cylinder_4 Calculate the content of shell the 1.6 m height cylinder with a base radius of 0.4 m.
  17. Cost reduction
    mp3_1 Two MP3 players whose price was equal to originally have been discounted the first by 20%, the second by 35%. After the price reduction was the difference in their prices 750, - CZK. What was the original price of each of the two players?
  18. Isosceles trapezoid
    rr_lichobeznik Calculate the circumference and the contents of the isosceles trapezoid if you know the size of the bases is 8 and 12 cm and the size of the arms is 5 cm.
  19. Two numbers
    fractal_6 The sum of the two numbers is 1. Find both numbers if you know that half of the first is equal to one seventh of the second number.
  20. Is right triangle
    triangle_1111_4 Decide if the triangle XYZ is rectangular: x = 4 m, y = 6 m, z = 4 m

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