Examples for 8th grade - page 77

  1. Circle - simple
    colorful-circle Calculate the area of a circle in dm2, if its circumference is 31.4 cm.
  2. Trio 2
    decide Decide whether trio of numbers is the side of a right triangle: 26,24,10.
  3. Trapezoid MO-5-Z8
    lichobeznik-stredni_pricka_2 Trapezoid KLMN has bases 12 and 4 cm long. The area of triangle KMN is 9 cm2. What is the area of the trapezoid KLMN?
  4. Cylinder surface area
    cylinder_2 Volume of a cylinder whose height is equal to the radius of the base is 678.5 dm3. Calculate its surface area.
  5. Flowerbed
    tulipany Family cultivated tulips on a square flower bed of 6 meters. Later they added the square terrace with a side of 7 meters to their house. One vertex of the terrace lay exactly in the middle of a tulip bed, and one side of the terrace divided the side of the
  6. Blueberries 2
    boruvky_2 Lenka and Martin collected eight liters of blueberries in two hours. How long will take to collect blueberries by Lenka itself, if we know that she collect all 2.5 hours less than Martin?
  7. Common cylinder
    valec_2 I've quite common example of a rotary cylinder. Known: S1 = 1 m2, r = 0.1 m Calculate : v =? V =? You can verify the results?
  8. Square roots
    roots What is equal to the product of the square roots of 295936?
  9. 2d shape
    semicircles_rect Calculate the content of a shape in which an arbitrary point is not more than 3 cm from the segment AB. The length of the segment AB is 5 cm.
  10. Theatro
    divadlo_1 Theatrical performance was attended by 480 spectators. Women were in the audience 40 more than men and children 60 less than half of adult spectators. How many men, women and children attended a theater performance?
  11. Cycling trip
    bus_7 At 8 am started a group of children from the camp to day cycling trip. After 9:00 weather deteriorated sharply and the leader decided to send for the children bus on the same route, which started at 10 hours. For how long and at what distance from the camp
  12. Sales off
    save_now Calculate what was the original price of the good, if the price after discount 25% and the subsequent rise of 20% is 400 USD.
  13. Potatoes
    zemiaky_3 Daniela and Michael would jointly dug potatoes for 7.5 hours. But if Daniela was working alone she would take 2.5 hours more as if he were working with Michael. Determine how much for the work done by Michael himself and how much Daniela herself.
  14. Log
    5962705_ad Worker cut his thick log to 6 pieces for 30 min. How long he cut log to 12 pieces?
  15. Addends
    two Number 118 divide into two addends, so first addend is 69 greater than 75% of the second addend.
  16. Pumps
    pumps Five pumps pumped 1,800 hl of water for 3 hours. How many hectoliters of water pump same two powerful pumps for six hours?
  17. Z7-I-4 stars 4949
    hviezdicky_mo Write instead of stars digits so the next write of product of the two numbers to be valid: ∗ ∗ ∗ · ∗ ∗ ∗ ∗ ∗ ∗ ∗ 4 9 4 9 ∗ ∗ ∗ ∗ ∗ ∗ 4 ∗ ∗
  18. Megapascals
    engine What is the area of crosssection of the piston, if the force of 300 kN produces a pressure of 5 MPa?
  19. Base, percents, value
    percent_1 Base is 344084 which is 100 %. How many percent is 384177?
  20. Trams
    tramvaje Two trams started at the same time from the same place. One tram journey takes 30 minutes and the second 45 minutes to its final stop. How long will trams meet again?

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