Examples for 8th grade - page 6

  1. Compare II
    powers Which of the numbers 158, 815 is greater?
  2. Tunnels
    Mysky Mice had built an underground house consisting of chambers and tunnels: • each tunnel leading from the chamber to the chamber (none is blind) • from each chamber lead just three tunnels into three distinct chambers, • from each chamber mice can get to any
  3. Area codes
    us_codes How many 6 digit area codes are possible if the first number can't be zero?
  4. Accidents
    nehoda-pomnik The count of accidents in 1993 caused 8009 women which is 7.1%. How many men caused the accidents?
  5. 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
  6. Madams
    womans During the spring cleaning ladies going to wash windows. Mother takes wash all the windows 5 hours, the grandmother 3 times longer and Paula wash all windows in 5 hours. How many hours will spend washing the windows this "women's team" if working togethe
  7. 2nd class variations
    cards From how many elements you can create 6480 variations of the second class?
  8. ABS
    sphere_nice What is the value of ? ?
  9. Radius
    green_circle Determine the radius of the circle, if its perimeter and area is the same number.
  10. Circle chord
    circleChord What is the length d of the chord circle of diameter 58 mm, if distance from the center circle is 24 mm?
  11. Kites
    drake Boys run kite on a cable of 86 meters long. What is the kite altitude, if the angle from the horizontal plane is 77°?
  12. Number
    percent What number is 24 % smaller than the number 51?
  13. Acreage
    parcela What acreage has a rectangular plot whose diagonal is 34 meters long and one side has a length of 16 meters. ?
  14. Garden
    garden_2 Father dig up the garden in 13 hours. Son in 18 hours. How many hours take dig up the garden together?
  15. 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?
  16. 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.
  17. Gauss
    kfgauss Help little C.F. Gauss sum all the integers from 1 to 340.
  18. Powers
    math_fun Is true for any number a,b,c,d equality:? ?
  19. Shadow and light
    stin Nine meters height poplar tree has a shadow 16.2 meters long. How long shadow have at the same time Joe if he is 1,4m tall?
  20. 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?

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