Examples for 8th grade - page 7

  1. Area of RT
    right_triangle_sepia Calculate the area of a right triangle which hypotenuse has length 20 and one hypotenuse segment has lenght 15.
  2. Present
    prezent Gift box has rectangular shape with dimensions of 3×3×5 cm. Martin wants to cover with square paper with sides of 10 cm. How much paper left him?
  3. Copiers
    images Three copiers will do the same in an hour k copies. How many copies would be done in an hour by four such copiers? ?
  4. Katy MO
    reporter_saved6 Kate draw triangle ABC. Middle of AB have mark as X and the center of the side AC as Y. On the side BC wants to find the point Z such that the content area of a 4gon AXZY was greatest. What part of the triangle ABC can maximally occupy 4-gon AXZY?
  5. Arc
    arc_1 Circle arc corresponding to angle is 193° is 23 dm long. What is the length of the entire circle?
  6. Octahedron - sum
    8sten On each wall of a regular octahedron is written one of the numbers 1, 2, 3, 4, 5, 6, 7 and 8, wherein on different sides are different numbers. For each wall John make the sum of the numbers written of three adjacent walls. Thus got eight sums, which also.
  7. Cubes
    rubik_cube Cube, which consists of 27 small cubes with edge 3 dm has volume:
  8. Sale
    sale_percent If the product twice price cut by 20%, what percentage was price cut in total?
  9. Circumscribing
    thales Determine the radius of the circumscribed circle to the right triangle with legs 3 cm and 3 cm.
  10. Lathe
    soustruh From the cube of edge 52 cm was lathed maximum cylinder. What percentage of the cube is left as waste after lathed?
  11. Wiring
    install_pipes Conduit has a cross section 492 mm. Maybe put it into 5 conductors with a cross section S2 $mm2?
  12. Phone numbers
    old_phone How many 9-digit telephone numbers can be compiled from the digits 0,1,2,..,8,9 that no digit is repeated?
  13. Internal angles
    mo-klm The ABCD is an isosceles trapezoid, which holds: |AB| = 2 |BC| = 2 |CD| = 2 |DA|: On its side BC is a K point such that |BK| = 2 |KC|, on its side CD is the point L such that |CL| = 2 |LD|, and on its side DA the point M is such that | DM | = 2 |MA|. Dete
  14. New refrigerator
    lednice New refrigerator sells for 878 USD, Monday will be 25% discount. How much USD will save, and what will be the price?
  15. Climb in percentage
    12_percent_stupanie The height difference between points A and B is 442 m. Calculate the percentage of route climbing if the horizontal distance places A, B is 6.8 km.
  16. Tetrahedral pyramid
    jehlanctyrboky What is the surface of a regular tetrahedral (four-sided) pyramid if the base edge a=23 and height v=8?
  17. Car inflation
    car_1 About what percentage price of car increased if price rose from €5000 to €5130?
  18. Clock
    hodiny How many times a day hands on a clock overlap?
  19. Friends in cinema
    cinema_1 5 friends went to the cinema. How many possible ways can sit in a row, if one of them wants to sit in the middle and the remaining's place does not matter?
  20. Lorry
    lorry The lorry was loaded with 27 boxes of 24 kg. How many boxes with weight 36 kg can be loaded, if total load must be same?

Do you have interesting mathematical example that you can't solve it? Enter it and we can try to solve it.



To this e-mail address we will reply solution; solved examples are also published here. Please enter e-mail correctly and check whether you don't have a full mailbox.