Examples for 8th grade - page 85

  1. Tailor master
    saty There are less than 50m of textile in the tailoring workshop. When cutting on a blouse (consumption 1.5m), no textile is left. When using a cloth (consumption of 3.2m), no textile is left. How many meters of textile are in a tailor's workshop?
  2. Two trains
    trains_1 There are two trains running the same distance. 1st train will travel it in 7 hours 21minutes. 2nd the train will travel 5 hours 57minutes and 34 seconds and it is 14 km/h faster than the first train. What are speeds of trains and how long is this railway
  3. Comparing salaries
    eura_5 Spouses compared salaries. Mrs. Janka found that a 20% higher salary than Mr Jaroslav. Together earned € 1,430. How much they earn each of them?
  4. Desribed circle to rectangle
    rectangle_in_circle_1 Rectangle with sides 6 cm and 4 cm was circumscribed circle. What part of the content of the circle determined by the circumscribed circle occupies a rectangle? Express in perctentages(%).
  5. Wall diagonal
    cube_6 Calculate the length of wall diagonal of the cube whose surface is 384 cm square.
  6. PC disks
    diskette Peter has 45 disks in three colors. One-fifth of the disks are blue, red are twice more than the white. How much is blue, red and white disks?
  7. Probably member
    math_series Look at the series 2,6,25,96,285, ? What number should come next?
  8. Unknown number
    5nums_1 Determine the unknown number, which double of its fourth square is equal the fifth its square.
  9. Rainfall
    rain_2 The annual average rainfall in India was in Cherrapunji in the year 1981 26 461 mm. How many hectoliters of water fell on 1 m2? Would fit this amount of water into a cube of three meters?
  10. Rhombus
    kosostvorec_6 If we increase the rhombus side by 2.4 cm; its perimeter is 20 cm. How long was the side of the rhombus?
  11. The cylinder base
    valec_4 The cylinder with a base of 8 dm2 has a volume of 120 liters. From a cylinder fully filled with water, 40 liters of water was removed. At what height from the bottom /with precision to dm/ is the water level?
  12. Blueberries
    blackberries Miko and Anton have a total of 1,580 blueberries. Miko and Anton have them in the ratio 2: 3. Determine how much each of them has.
  13. 3 masons
    cnb_1 3 masons received 7,700 CZK. The second half received 1/2 more than the first and third twice more than the second mason. How much they each got crowns?
  14. Doubling
    exp_5 The message is spreading that each day has doubled the number of people who know about it. All know message for 20 days. How long known it eighth people?
  15. Cows
    cow_3 Agricultural cooperative has increased the number of housed cows by 14% to 285 units. By how many cows increased agricultural cooperative the number of cows?
  16. Regular n-gon
    regular_polygons Which regular polygon have a radius of circumscribed circle r = 10 cm and the radius of inscribed circle p = 9.962 cm?
  17. Jane class
    students When asked how many students are in class, Jane said, if we increase the number of students in our class by hundred % and then add half the number of students, we get 100. How many students are in Jane's class?
  18. Cube walls
    krychle_6 Find the volume and surface area of the cube if the area of one wall is 40cm2.
  19. Diagonals in diamons/rhombus
    diamonds Rhombus ABCD has side length AB = 4 cm and a length of one diagonal of 6.4 cm. Calculate the length of the other diagonal.
  20. Volleyball
    volejbal 8 girls wants to play volleyball against boys. On the field at one time can be six players per team. How many initial teams of this girls may trainer to choose?

Do you have an interesting mathematical word problem that you can't solve it? Enter it, and we can try to solve it.



To this e-mail address, we will reply solution; solved examples are also published here. Please enter the e-mail correctly and check whether you don't have a full mailbox.

Please do not submit problems from current active competitions such as Mathematical Olympiad, correspondence seminars etc...