Examples for 8th grade - page 4

  1. Cube diagonal
    cube_diagonal Determine length of the cube diagonal with edge 91 dm.
  2. Exam average
    vysvedcenie_2 Average of marks that have on the certificates students of 8.A class in mathematics is exactly 2.45. If we did not add 1 and 3 of sutdents Michael and Alena, who arrived a month ago, it would average exactly 2.5. Determine how many students have class 8.
  3. Pizza master
    pizza_3 Master says that he can splits pizza to 16 parts by five equals straight cuts. Is it possible?
  4. Tractors
    tractor 6 tractors started plowing the field that them together take 12 days. Agronomist hesitates to A) after 2 days to withdraw 2 tractors, or B) after 3 days to withdraw 3 tractors. Help him which of these two cases will be plowing done sooner.
  5. Square diagonal
    square_d Calculate length of the square diagonal if the perimeter is 200 cm.
  6. Number ratio
    ratio2 Calculate two positive numbers that its ratio is 4:4 and sum was 184.
  7. 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
  8. Sequence
    arithmetic_seq In the arithmetic sequence is a1=-9, d=4. Which member is equal to the number 147?
  9. Square diagonal
    square_diagonal Calculate the length of diagonal of the square with side a = 23 cm.
  10. Bonus
    moeny Gross wage was 1113 USD including 16% bonus. How many USD were bonuses?
  11. Invitations
    envelope For every 5 minutes writes Dana 10 invitations, while Anna 14 invitations. How long will write together 120 invitations?
  12. OK circle
    circles2 Calculate the radius (circumradius) of the circle described right triangle with hypotenuse long 8 and one cathetus long 4.
  13. Permill
    permille How many permill is 1931 from 166456?
  14. 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.
  15. Compare II
    powers Which of the numbers 158, 815 is greater?
  16. 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
  17. 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
  18. ABS
    sphere_nice What is the value of ? ?
  19. Area codes
    us_codes How many 6 digit area codes are possible if the first number can't be zero?
  20. 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?

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