Examples for 8th grade - page 58

  1. Grid/network of cube
    siet_kocky Grid of cube has a circumference 42 mm. Calculate the surface area of the cube ...
  2. Tank 9
    water_cocks The tank with volume V is filled with one pump for three hours and by second pump for 5 hours. When both pumps will run simultaneously calculate: a) how much of the total volume of the tank is filled in one hour b) for how long is the tank full
  3. Colour - billboard
    rovnobeznik_1 Shelftalker has the shape of a parallelogram. Its length is 4.9 m and the corresponding height is 3.5 meters. Calculate how much (kg) paint must purchase to redecoration if 1 kg cover 4 m2 of shelftalker surface.
  4. Scale of the map
    meritko Determine the scale of the map if the actual distance between A and B is 720 km and distance on the map is 20 cm.
  5. ABS
    sphere_nice What is the value of ? ?
  6. Star
    cross_star Calculate the content of the shaded part of square with side 19 cm.
  7. Cube 9
    MD_cheese_cubes What was the original edge length of the cube if after cutting 39 small cubes with an edge length 2 dm left 200 dm3?
  8. Body diagonal
    kvadr Cuboid with base 7cm x 3,9cm and body diagonal 9cm long. Find the height of the cuboid and the length of the diagonal of the base,
  9. Areaf of ST
    triangle-inside-square It is given square DBLK with side |BL|=13. Calculate area of triangle DKU if vertex U lie on line LB.
  10. 6-gon
    hexagons Perimeter of regular hexagon is 113. Calculate its circumradius (radius of circumscribed circle).
  11. Square - increased perimeter
    rectangles_4 How many times is increased perimeter of the square, where its sides increases by 150%? If the perimeter of square will increase twice, how much% increases the content area of the square?
  12. Painting school
    painting Redecoration school had scheduled for four crew to 10 days. After two days a single worker ill. For how many days the school was painted when remain workers working with the same tempo?
  13. Slope form
    lines_2 Find the equation of a line given the point X(8, 1) and slope -2.8. Arrange your answer in the form y = ax + b, where a, b are the constants.
  14. Copy typist
    pisaci_stroj Typist for 12 hours rewritten 15% of the manuscript. After how many hours he will done 35% of the manuscript?
  15. Holiday SMS
    sms Kucera and Malek start from the holiday together. They agreed that if they be 100 km apart, will send a SMS. Kucera traveling at 60 km/h., Malek 90 km/h. They started at 14 hours PM. At what time they send a message?
  16. Classs mean
    nums Class size is 30 students, math was not worse than sign 2. Determine the number of pupils who were sign 1 if the class had a 1.4 sign average.
  17. Seven tractors
    koleso Seven tractor plowed 308 ha field in four days. How many hectares of fields will plowe 9 tractors in 3 days at the same power?
  18. Triangle eq
    rs_triangle_1 Calculate accurate to hundredths cm height of an equilateral triangle with a side length 12 cm. Calculate also its perimeter and content area.
  19. Three friends
    three_friends Peter is eight times older than Rado, Rado is 3 times younger than Joseph. Together they have 120 years. Determine how many are each of them.
  20. Washing machine
    washing_masine The price of washing machine was decreased by 21% and then by 55 € due small sales. After two price decreases cost € 343. How much was originally cost?

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