Examples for 8th grade - page 48

  1. Painters
    3_painters One painter could paint a school for 7 days. The second one for 6 days. It was necessary to paint the school in two days. Next painter was invited and all worked together. How long would this painter painted the school itself?
  2. Flowerbed
    zahon_5 The flowerbed has a length 3500mm and a width 1400mm. How many foil is needed to covers the flowerbed? How many m2 of foil was consumed for its production (add 10% of the material to the joint and waste)? How many liters of air is inside the enclosure? (F
  3. Rectangles - sides
    rectangles_2 One side of the rectangle is 25 cm longer than second. Shortens longer side by 14 cm and extend shorter by 13 cm increases the area of the rectangle by 130 cm2. What are the dimensions of the original rectangle?
  4. Diplomas
    diploma Suzanne helped write out diplomas. Issuance its first took 4 minutes, each next 2.4 minutes. How much time it will take to write out n=23 diplomas (including the first), write out this pace?
  5. Brackets
    brackets Place one pair of brackets in expression 20-16 + 10 - 4 - 2 so that the result will be 0.
  6. Three piles
    sugar 100 kg of sugar we divide into three piles. The first pile is small. If we added to second 2 kg of sugar it would have 25% more sugar than the first pile. If we added to third pile 3 kg of sugar it would have 20% more sugar than the 2nd pile. How many kil
  7. Cyclist
    cyklista Cyclist rode two-fifths of the way the first day. The second day drove 5 km less while traveled three-eighths of route. How many kilometers does he have to finish target?
  8. Nectar
    vcela Nectar collected by bees contains 70% water. From the nectar of the some process produces honey which contains 19% water. How many kg of nectar bees need to collect to make 1 kg of honey?
  9. Equilateral triangle v2
    eq_triangle Equilateral triangle has a perimeter 36 dm. What is its area?
  10. Polygon 42
    12gon Which polygon has 42 more diagonals than sides?
  11. Glass
    pohgar How many glass are needed to produce glass with base regular 5-gon if one base triangle in the base is 4.2 square cm and the height is 10 cm?
  12. Seamstress
    krajcirka Seamstress bought two kinds of textile together 25 meters. One at 50 SKK and the second 70 SKK per meter. How many meter bought from this two textiles when paid totally 1540 SKK?
  13. Wheel diameter
    koleso_1 A 1m diameter wheel rolled along a 100m long track. How many times did it turn?
  14. Children
    weight_1 Margaret and Zdena weighs the same and Petra 3 kg more. Together weigh 156 kg. How much does they weigh?
  15. Is right triangle
    rt.JPG One angle of the triangle is 36° and the remaining two are in the ratio 3:5. Determine whether triangle is a rectangular triangle.
  16. 9-gon
    9gon Sum of interiol angles of 9-gon is:
  17. 10 pieces
    circle_div How to divide the circle into 10 parts (geometrically)?
  18. Crowns
    money_4 1180 crowns is divided into three people that A got 20% less than B and C by 15% more than B. How many got A,B and C?
  19. Silver medal
    circle_1 To circular silver medal with a diameter of 10 cm is inscribed gold cross, which consists of five equal squares. What is the content area of silver part?
  20. Rings groups
    venn 27 pupils attend some group; dance group attends 14 pupils, 21 pupils sporty group and dramatic group 16 pupils. Dance and sporting attend 9 pupils, dance and drama 6 pupil, sporty and dramatic 11 pupils. How many pupils attend all three groups?

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