Examples for 8th grade - page 44

  1. Map scale
    garden_5 Garden has on plan on a scale of 1: 150 width 22 cm and length 35 cm. What is the real area of the garden?
  2. Cosine
    cosine The point (21, 20) is on the terminal side of angle θ. cos θ = ?
  3. Cuboid - simple
    cuboid_6 Calculate the surface area and volume of a cuboid if a = 8 cm, b = 14 cm and c = 6 cm.
  4. Midpoint of segment
    midpoint-segment Point A has coordinates [15; 1] and the midpoint of the segment AB is the point [-20; 13]. What are the coordinates of point B?
  5. Trees
    trees_1 Loggers wanted to seed more than 700 and less than 800 trees. If they seed in rows of 37, left them 8 trees. If they seed in rows of 43, left the 11 trees. How many trees must seed ?
  6. The carpet
    koberec_1 How many meters of carpet 90 cm wide need to cover floor room which has a rectangular shape with a lengths 4.8 m and 2.4 m if the number of pieces on the carpet is needed to be lowest?
  7. Semicircle
    semicircle_2 To a semicircle with diameter 10 cm inscribe square. What is the length of square sides?
  8. Chicken and rabbits (classic)
    zajace Grandmother breeding chickens and rabbits. It found that the yard has 22 heads and 66 legs. How many chickens and rabbits breeding in the yard?
  9. Concentric circles
    chord_2 In the circle with diameter 17 cm is constructed chord 12 cm long. Calculate the radius of a concentric circle that touches this chord.
  10. Miraculous tree
    tree Miraculous tree grows so fast that the first day increases its height by half the total height of the second day by the third, the third day by a quarter, etc. How many times will increase its height after 8 days?
  11. Flowerbed
    flowers On the flowerbed was planted 310 flowers - pansies and crayons. During the first week wilts quarter of pansies and an eighth crayons, which is 20% of all flowers. How many pansies were planted on the flowerbed?
  12. Soup
    polevka 61% of pupils at the school to eat in the canteen, 1/61 of students who eat in the canteen eat lunch soup. a) What percentage of pupils who eat in the canteen and eat soup for lunch? b) What percentage of all pupils of school eat lunch soup?
  13. Tractor wheels
    kola Smaller tractor wheel has a circumference of 3 meters, bigger 4 meters. On what path executes smaller wheel 6 turns over more bigger?
  14. Five tractors
    tractor_1 Five tractors plow field in 4.8 hours. How long plow this field if after 1.5 hours of work two tractors went to a different field?
  15. VAT
    leganza In the country XYZ car Daewoo Leganza costs 3779 Euros including VAT; 3325.52 Eur without VAT. a) Determine the rate of VAT. b) How much is Euro VAT paid on the purchase? c) How many % of the total price of the goods is VAT? VAT = value added tax.
  16. Saw
    kotuc Imagine that the saw blade with diameter 35 cm has one tooth colored with a different color. How long is path describing by the tip of the tooth after 7 minutes, if the blade is rotated 4704 times?
  17. Road - permille
    18procent 5 km long road begins at an altitude 500 meters above sea level and ends at a altitude 521 ASL. How many permille road rises?
  18. Three numbers
    fun3_8 The sum of the three numbers is 287. These numbers are in a ratio of 3: 7: 1/4 Define these numbers
  19. Painting rooms
    palma_1 If Dano paint three hours daily given work he complete in 7.5 days. How many hours a day would have to work to finish the job 1.5 days earlier?
  20. The dice
    hracia-kocka What is the probability of events that if we throw a dice is rolled less than 6?

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