Examples for 8th grade - page 57

  1. Regular triangular prism
    3b_hranol Calculate the surface area of body of regular triangular prism, when the length of its base edge is 6.5 cm and height 0.2 m.
  2. Shepherd
    sheep_1 The shepherd has fewer than 500 sheep; where they can be up to 2, 3, 4, 5, 6 row is always 1 remain, and as can be increased up to 7 rows of the sheep, and it is not increased no ovine. How many sheep has a shepherd?
  3. Siblings
    tri-sourozenci Three siblings had saved up a total of 1,274 CZK. Peter had saved up to 15% more than Jirka and Hanka 10% less than Peter. How much money they saved each one of them?
  4. Basketball
    friends_1 Peter and Franta threw to the basket. Each had 20 attempts. Peter scored thirteen and twelve Franta. Give them success in percentage.
  5. 3 days
    kontrolor Worker checked 2,950 products in 3 days. Second day checked 25% more than the first day. The third day 15% more products than the second day. How many products he checked in each day.
  6. Office
    hranol-6u Office building was built in the shape of a regular hexagon inscribed in a circle with a radius of 12 m. The height of the walls is 7m. How much CZK cost plastering the walls of the building, if per 1 m square cost CZK 400?
  7. Parallelogram ABCD
    paralleogram_1 The area of parallelogram ABCD is 440 cm2. Points M and N are the midpoints of the sides AB and BC. What is the area of a quadrilateral MBND?
  8. Waiting room
    fly In the waiting room are people and flies. Together they have 15 heads and 50 legs (fly has 6 legs). How many people and flies are in the waiting room?
  9. Candelas
    sviecky We burned two unequally thick and long candles. Longer burnt for three and a half hours and shorter for five hours. After two hours of burning it was identical. How many times was longer candle longer then shorter?
  10. Price reduction
    camera Price of camera is 654 USD on sale its price reduced to 411 USD. Calculate the percentage reduction in the price of the camera.
  11. Unknown number 5
    seven I think unknown number. If we enlarge it five times then subtract 3 and result decreases by 75% we get the number by one greater than the number I think. What number am I thinking?
  12. Strange x
    pie For what x is true ??
  13. Average height
    vyska In a class are 34 students. The average height of students is 165 cm. What will be the average height of students in the classroom when two pupils tall 176 cm and 170 cm moved from this school/class?
  14. Dog
    stvorec_1 Dog is tied to a chain, which is mounted in a corner of the yard. Yard has the shape of a square with a side length of 20 meters. The same long is also dogchain. Are there places in the yard where dog can't reach?
  15. Children
    car_game Less than 20 children is played various games on the yard. They can create a pairs, triso and quartets. How many children were in the yard when Annie came to them?
  16. Reservoir
    cylinder_Au 6 m long reservoir has a diameter of 2.2 m. What is its surface area in square meters?
  17. 5 pumps
    pump Five pump to pump 3 hours 1600 hl of water. How long pumped same amount of water 4 pumps?
  18. Mr. Vojta
    penize Mr. Vojta put in the bank 35000 Kč.After a year bank him credited with interest rate of 2% of the deposit amount. How then will Mr. Vojta in the bank?
  19. Volume of three cuboids
    image10 Calculate the total volume of all cuboids for which the the size of the edges are in a ratio of 1:2:3, and one of the edges has a size 6 cm.
  20. Concentration
    ocet_1 How 0.5 liters of 8% vinegar diluted to a concentration of 20 hundredths % of vinegar? How many liters of water must be pour?

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