Examples for 8th grade - page 39

  1. Scouts
    icons Three scouts went on a three day trip. The second day went 4 km more than the first day. The third day went two times less than the first day. They went along 54 km. How many kilometers went every day together?
  2. Cylinder
    cylinder The cylinder surface is 139 dm2, its height is equal to the radius of the base. Calculate height of this cylinder.
  3. Equator
    around_globe Suppose that tourist went on foot over the Globe equator. How many meters more track made ​​his hat on his head as the shoes on your feet? The radius of the earth is 6378 km and height of the tourist is 1.7 m.
  4. Digits A, B, C
    numbers_8 For the various digits A, B, C is true: the square root of the BC is equal to the A and sum B+C is equal to A. Calculate A + 2B + 3C. (BC is a two-digit number, not a product).
  5. Diagonal in rectangle
    q In that rectangle ABCD is the center of BC point E and point F is center of CD. Prove that the lines AE and AF divide diagonal BD into three equal parts.
  6. Word problem
    hungary-flag 384 students were on holiday in Hungary. 146 bought pizza, chips 25 pupils, 39 pupils bought soda, butter 15 pupils, 18 pupils fruits, vegetables 29 students. How much pay for all the food, if every meal cost 4.9 euros?
  7. Cuboid aquarium
    cuboid Cuboid 25 times 30 cm. How long is third side if cuboid contains 30 liters of water?
  8. Comparing powers
    diagram How many times is number 55 larger than number 45?
  9. Nuts, girl and boys
    orechy_nuts Milena collected fallen nuts and called a bunch of boys let them share. She took a condition: the first boy takes one nut and tenth of the rest, the second takes 2 nuts and tenth new rest, the third takes 3 nuts and tenth new rest and so on. Thus managed.
  10. Pool 2
    bazen_pritok The first supply by the pool fill for five hours and the second fill for six hours, drain should be drained for 15 hours. For how many hours the pool is full, when we open both inlet now and outlet open two hours later?
  11. Medal
    gold_medail Calculate the approximate weight of the gold Olympics medal, if its diameter is 9 cm and a thickness 6 mm. The density of gold find out in the tables or on the Internet.
  12. Two boxes-cubes
    3-kostky Two boxes cube with edges a=74 cm and b = 91 cm is to be replaced by one cube-shaped box (same overall volume). How long will be its edge?
  13. Bouquet
    flowers_1 Gardener tying bouquet of flowers for 8 and none was left. Then he found that he could tying bouquet of 6 flowers and also none was left. How many have gardener flowers (minimum and maximum) if they had between 50 and 100 flowers?
  14. Acute angles
    angles_meter Sizes of acute angles in the right-angled triangle are in the ratio 1: 6. What is size of the larger of them?
  15. Vinegar
    vinegar_1 What percentage vinegar we get if we mix 1 if dm³ eight percent vinegar with 1.5 dm³ six percent vinegar?
  16. Round table
    obrus-kruhovy Round table with diameter d = 95 cm is coated by square tablecloth with a side length 122 cm. About how many cm is higher center of tablecloth than its cornes?
  17. Arc
    vysek What area of a circle occupied the flowers planted in the arc of a circle with radius 2 m with central angle 45°?
  18. Freight and passenger car
    1999_Daewoo_Leganza The truck starts at 8 pm at 30 km/h. Passenger car starts at 8 pm at 40 km/h. Passenger arrives in the destination city 1 hour and 45 min earlier. What is the distance between the city of departure and destination city?
  19. Barrel with liquid
    barrel Barrel with grain weight 263 kg. When it shed 43% of grain, ha weight 170 kg. What is the weight of empty barrel?
  20. Square Number
    squared-number If to a square of integer number add 49, we get the square of next integer number. What is the original number?

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