Examples for 8th grade - page 6

  1. Number ratio
    ratio2 Calculate two positive numbers that its ratio is 4:4 and sum was 184.
  2. Square diagonal
    square_diagonal Calculate the length of diagonal of the square with side a = 23 cm.
  3. Z9-I-4
    numbers_30 Kate thought a five-digit integer. She wrote the sum of this number and its half at the first line to the workbook. On the second line wrote a total of this number and its one fifth. On the third row she wrote a sum of this number and its one nines. Fi
  4. Invitations
    envelope For every 5 minutes writes Dana 10 invitations, while Anna 14 invitations. How long will write together 120 invitations?
  5. Permill
    permille How many permill is 1931 from 166456?
  6. Compare II
    powers Which of the numbers 158, 815 is greater?
  7. 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
  8. Area codes
    us_codes How many 6 digit area codes are possible if the first number can't be zero?
  9. 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
  10. ABS
    sphere_nice What is the value of ? ?
  11. 2nd class variations
    cards From how many elements you can create 6480 variations of the second class?
  12. Radius
    green_circle Determine the radius of the circle, if its perimeter and area is the same number.
  13. 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?
  14. Number
    percent What number is 24 % smaller than the number 51?
  15. Garden
    garden_2 Father dig up the garden in 13 hours. Son in 18 hours. How many hours take dig up the garden together?
  16. 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?
  17. Accidents
    nehoda-pomnik The count of accidents in 1993 caused 8009 women which is 7.1%. How many men caused the accidents?
  18. 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.
  19. Powers
    math_fun Is true for any number a,b,c,d equality:? ?
  20. Gauss
    kfgauss Help little C.F. Gauss sum all the integers from 1 to 340.

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