Examples for 8th grade - page 5

  1. Sequence
    arithmetic_seq In the arithmetic sequence is a1=-9, d=4. Which member is equal to the number 147?
  2. 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
  3. Number ratio
    ratio2 Calculate two positive numbers that its ratio is 4:4 and sum was 184.
  4. Square diagonal
    square_diagonal Calculate the length of diagonal of the square with side a = 23 cm.
  5. Bonus
    moeny Gross wage was 1113 USD including 16% bonus. How many USD were bonuses?
  6. OK circle
    circles2 Calculate the radius (circumradius) of the circle described right triangle with hypotenuse long 8 and one cathetus long 4.
  7. Invitations
    envelope For every 5 minutes writes Dana 10 invitations, while Anna 14 invitations. How long will write together 120 invitations?
  8. Permill
    permille How many permill is 1931 from 166456?
  9. 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
  10. Pool
    swimming-pool The swimming pool is 6 m wide and 14 m long and 185 cm deep. How many hectoliters of water is in it, if the water is 9 cm below its upper edge.
  11. Compare II
    powers Which of the numbers 158, 815 is greater?
  12. 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
  13. ABS
    sphere_nice What is the value of ? ?
  14. Area codes
    us_codes How many 6 digit area codes are possible if the first number can't be zero?
  15. 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?
  16. Radius
    green_circle Determine the radius of the circle, if its perimeter and area is the same number.
  17. 2nd class variations
    cards From how many elements you can create 6480 variations of the second class?
  18. Garden
    garden_2 Father dig up the garden in 13 hours. Son in 18 hours. How many hours take dig up the garden together?
  19. 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?
  20. Number
    percent What number is 24 % smaller than the number 51?

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