Examples for 8th grade - page 59

  1. Earth's surface
    earth_globe The greater part of the earth's surface (r = 6371 km) is covered by oceans; their area is approximately 71% of the Earth's surface. What is the approximate area of the land?
  2. Tram
    tramvaj-skoda In the three-part tram went 109 passengers in front of others, 92 after others and in the middle half of all. How many passengers went in tram total?
  3. Coal
    coal If the daily consumption of 1.6 tons of coal, it is sufficient to supply the boiler for 42 days. How long is sufficient to supply when will burn only 1.2 tons of coal a day ?
  4. Trapezoid thirds
    lichobeznik_mo_z8_3 The ABCD trapezoid with the parallel sides of the AB and the CD and the E point of the AB side if the segment DE divides the trapezoid into two parts with the same area. Find the length of the AE line segment.
  5. Plan scale
    geodet At what scale is drawn plan of the building, where one side of the building is 45 meters long is on the plan expressed by a straight line 12 mm long.
  6. 4 pipes
    roury The tank flows out by 4 pipes in 6 hours 120 hl water. How much water flows out of 5 pipes of the same diameter in 14 hours?
  7. Minute
    compass Two boys started from one place. First went north at velocity 3 m/s and the second to the east with velocity 4 m/s. How far apart they are after minute?
  8. Rope slack
    rope_slack Between two streets 20 m away give the lamp, which is in the middle and hanging 60 cm bellow the taut rope. Can be done with 20.5 meters rope?
  9. Sines
    sines In ▵ ABC, if sin(α)=0.5 and sin(β)=0.1 calculate sin(γ)
  10. Brigade
    smrek_1 On a weekly forest brigade operates 12 students. After plant one hundred spruces get x CZK, anfter one hundred pines y CZK. How many CZK got one student for one day if planted spruces 25000 and 30000 pines week?
  11. Well
    well Rope with a bucket is fixed on the shaft with the wheel. The shaft has a diameter 60 cm. How many meters will drop bucket when the wheels turn 15 times?
  12. Wheel
    bicycle_1 Diameter of motocycle wheel is 63 cm. How many times rotates wheel on roand long 1 km?
  13. Square garden
    garden_4 On the plan with a scale of 1:1500 is drawn as a square garden with area 4 cm2. How many meters is long garden fence? Determine the actual acreage gardens.
  14. Sisters
    sestry20091 Sisters Janka and Danka are saved together 220 CZK. On a trip to Janka wants to take a fifth of her savings and Danka quarter. Then they will have 50 CZK on the trip. How much money saved Janka and Danka?
  15. New refrigerator
    lednice New refrigerator sells for 878 USD, Monday will be 25% discount. How much USD will save, and what will be the price?
  16. Tiles
    wall-tiles-img-5 How many square tiles with the content 121 cm2 has to be ordered for the paving of the square room with a side length of 2.75 meters?
  17. Hexagon = 8 parts
    stef.6.11.99 Divide the regular hexagon into eight equal parts.
  18. Solutions
    bilde How much 60% solution and how much 35% solution is needed to create 100 l of 40% solution?
  19. Three numbers
    numbers_9 Find three numbers so that the second number is 4 times greater than the first and the third is lower by 5 than the second number. Their sum is 67.
  20. Sugar
    cukr Sugar factory produced 938.1 tons of sugar in 1 day at 14% sugar content . How many tons of pure beet sugar factory processed in 1 day?

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