Examples for 8th grade - page 5

  1. Radius
    green_circle Determine the radius of the circle, if its perimeter and area is the same number.
  2. 2nd class variations
    cards From how many elements you can create 6480 variations of the second class?
  3. Excavation
    vykop_ryha Mr. Radoslav calculated that excavation for a water connection dig for 10 days. His friend would take 7 days. Radoslav worked 3 days alone. Then his friend came to help and started on the other end. On what day since the beginning of excavation they met?
  4. Garden
    garden_2 Father dig up the garden in 13 hours. Son in 18 hours. How many hours take dig up the garden together?
  5. Number
    percent What number is 24 % smaller than the number 51?
  6. Powers
    math_fun Is true for any number a,b,c,d equality:? ?
  7. 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?
  8. Gauss
    kfgauss Help little C.F. Gauss sum all the integers from 1 to 340.
  9. 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?
  10. River
    kongo_river Calculate how many promiles river Hudson average falls, if on section long 921 km flowing water from 1224 m AMSL to 154 m AMSL.
  11. Two workers
    Frog Two workers together execute some work in 10 days. The first worker would have done himself in 20 days. How many days would have done himself a second worker?
  12. Accidents
    nehoda-pomnik The count of accidents in 1993 caused 8009 women which is 7.1%. How many men caused the accidents?
  13. 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.
  14. Lathe
    soustruh From the cube of edge 52 cm was lathed maximum cylinder. What percentage of the cube is left as waste after lathed?
  15. Arc
    arc_1 Circle arc corresponding to angle is 193° is 23 dm long. What is the length of the entire circle?
  16. Sale
    sale_percent If the product twice price cut by 20%, what percentage was price cut in total?
  17. Ravens
    krkavec The tale of the Seven Ravens were seven brothers, each of whom was born exactly 1.5 years after the previous one. When the eldest of the brothers was 4-times older than the youngest, mother all curse. How old was seven ravens brothers when their mother cur
  18. Cubes
    rubik_cube Cube, which consists of 27 small cubes with edge 3 dm has volume:
  19. Wiring
    install_pipes Conduit has a cross section 222 mm. Maybe put it into 6 conductors with a cross section S2 $mm2?
  20. Acreage
    parcela What acreage has a rectangular plot whose diagonal is 34 meters long and one side has a length of 16 meters. ?

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