Examples for 8th grade - page 21

  1. 4s pyramid
    pyramid_regular Regular tetrahedral pyramid has a base edge a=6 and collaterally edge length b=15. What is its height?
  2. Runners circle
    runners Pepa circles the track in 36 seconds. Kamil in 42 seconds. They started together. How many seconds will meet again at the start?
  3. Plums
    plumbs In the bag was to total 193 plums. Igor took 4 plums and Mary took 4/7 from the rest. How many plums remained in the bag?
  4. Isosceles trapezoid v3
    rovnobezky_uhly In an isosceles trapezoid ABCD is the size of the angle β = 71° Determine size of angles α, γ and δ.
  5. The chord
    Tetiva Side of the triangle inscribed in a circle is a chord passing through circle center. What size are the internal angles of a triangle, if one of them is 40°?
  6. Aunt
    teta Annie aunt is 35 years old, Annie is 14 years. For how many years will aunt have twice as many years as Annie?
  7. Height
    equilateral_triangle Calculate height of the equilateral triangle if its perimeter is 54?
  8. Sphere A2V
    sphere3 Surface of the sphere is 306 m2. What is its volume?
  9. Tractors
    tractor_2 Six tractors plowing the field for 8 days. After two days, two tractors broke down. How many days were prolonged work in the field?
  10. Is right?
    RightTriangleSquares Determine whether the triangle with cathetuses 19.5 cm and 26 cm and length of the hypotenuse 32.5 cm is rectangular?
  11. Sheep
    ships Shepherd tending the sheep. Tourists asked him how much they have. The shepherd said, "there are fewer than 500. If I them lined up in 4-row 3 remain. If in 5-row 4 remain. If in 6-row 5 remain. But I can form 7-row." How many sheep have herdsman?
  12. Vacation
    dovolenka Smiths paid a deposit for a vacation of two-sevenths of the total price of the vacation. Then paid also € 550. How much cost their vacation?
  13. Copy typist
    pisaci_stroj Typist for 12 hours rewritten 15% of the manuscript. After how many hours he will done 35% of the manuscript?
  14. Dog
    dog_and_man Man goes with a dog on a long walk 18 km from the house. Man is walking at speed 5.3 km/h and a dog that constantly running between house and man at 17.1 km/h. How many kilometers will run the dog when they reach their destination?
  15. Prism X
    hranol The prism with the edges of the lengths x cm, 2x cm and 3x cm has volume 48000 cm3. What is the area of surface of the prism?
  16. Cyclist
    sagan A cyclist is moving at 26 km/h and follow pedestrian who is walking at speed 7 km/h. Walker has an advantage 13 km. How long take cyclist to catch up with him?
  17. Trip
    pomarancovy-dzus On the trip drank 3/10 of pupils tea, 2/5 cola, 1/4 mineral water and remaining 3 juice. How many students were on the trip?
  18. Base, percents, value
    percent_1 Base is 344084 which is 100 %. How many percent is 384177?
  19. Decomposition
    prime_factorization Make decomposition using prime numbers of number 355. Result write as prime factors (all, even multiple)
  20. 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?

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