Examples for 8th grade - page 57

  1. 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?
  2. 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?
  3. 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?
  4. Copy typist
    pisaci_stroj Typist for 12 hours rewritten 15% of the manuscript. After how many hours he will done 35% of the manuscript?
  5. Isosceles triangle
    triangles_8 Calculate area and perimeter of an isosceles triangle ABC with base AB if a = 6 cm, c = 7 cm.
  6. Average height
    vyska In a class are 34 students. The average height of students is 165 cm. What will be the average height of students in the classroom when two pupils tall 176 cm and 170 cm moved from this school/class?
  7. 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.
  8. 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?
  9. 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.
  10. 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.
  11. QuizQ2
    debil_z_tv The square of the first number is equal to three-fifths of the second number. Determine both numbers if you know that the second number is 5 times greater than the first, and neither of numbers is not equal to zero.
  12. Grid/network of cube
    siet_kocky Grid of cube has a circumference 42 mm. Calculate the surface area of the cube ...
  13. The rod
    pascolour The rod is painted in four colors. 55% of the bar is painted in blue, green 0.2 of rod, 1/8 is brown and the remaining 45 cm of white. How long is rod?
  14. 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?
  15. Divide money 2
    penize_42 Ben and Dan had the same amount of money at the start. When Ben gave 300 to Dan, the ratio of Ben 's money to Dan's money became 2:3. How much money did each have at first?
  16. Chord 3
    chords What is the radius of the circle where the chord is 2/3 of the radius from the center and has a length of 10 cm?
  17. Park
    diamond_3 In the park is marked diamond shaped line connecting locations A, D, S, C, B, A. Calculate its length if |AB| = 108 m, |AC| = 172.8 m.
  18. 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.
  19. Bookshelve
    money_15 Bookshelve with an original price of € 200 twice become cheaper. After the second discounted by 15% the price was € 149.60. Determine how much % become cheaper for the first time.
  20. Kitchen
    valcek_na_cesto Kitchen roller has a diameter 70 mm and width of 359 mm. How many square millimeters roll on one turn?

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