Examples for 8th grade - page 44

  1. 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.
  2. 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?
  3. 6 regular polygon
    hexagon_2 It is given 6 side regular polygon whose side is 5 cm. Calculate its content area. Compare how many more cm2 (square centimeters) has a circle in which is inscribed the 6-gon.
  4. Circular flowerbed
    sustredene_kruznice Circular flowerbed with diameter 8 m we split by concentric circle to circle and annulus with the same area. Determine the radius of the circle.
  5. Water reservoir
    nadrz_3 The water reservoir is filled with one pump for 4 days by the second one for 9 days. Outlet can drain tank in 12 days. How long take fill the reservoir if both pumps are running and not closed outlet channel.
  6. Reciprocal
    inverse It is true (prove it) that if a> b> 0: ?
  7. 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?
  8. 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?
  9. Dig water well
    studna_2 Mr. Zeman digging a well. Its diameter is 120 cm, and plans to 3.5 meters deep. How long (at least) must be a ladder, after which Mr. Zeman would have eventually come out?
  10. 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?
  11. Chess
    chess How many different ways can initiate a game of chess (first pass)?
  12. Influenza
    flu For the first week of February by influenza 5% of children in kindergarten. The second week ill 9 next children, bringing the number of patients increased to 20%. How many children went to the kindergarten?
  13. Moon
    zem_mesic We see Moon in the perspective angle 28'. Moon's radius is 1740 km at the time of the full moon. Calculate the mean distance of the Moon from the Earth.
  14. Grandfather
    family_16 The grandfather is three years older than an grandmother. The average age of the grandmother, the grandfather and their seven grandchildren is 28 years. The grandchildren have a total of 105 years. Calculate how old is grandfather.
  15. 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?
  16. The dice
    hracia-kocka What is the probability of events that if we throw a dice is rolled less than 6?
  17. Semicircle
    semicircle_2 To a semicircle with diameter 10 cm inscribe square. What is the length of square sides?
  18. Znojmo
    car_3 From Znojmo to Brno started truck with a trailer at an average speed 55 km per hour. Against him 18 minutes later from Brno started car with an average speed of 1.2-times greater than the truck. How long and how far from Znojmo, they meet if the distanc
  19. Prism
    prism The volume of tetrahedral prism is 2.43 m3. Base of prism is a parallelogram in which a side 2,5dm and height ha = 18cm. Calculate the height of the prism.
  20. A three-digit numbers
    clocks_1 Determine the total number of positive three-digit numbers that contain a digit 1.

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