Examples for 8th grade - page 78

  1. Trees - orchard
    jablone_2 The 3/5 trees are apple trees and 1/3 of the trees are cherries. The remaining 5 trees are pear trees. How many trees are in the orchard.
  2. Image scale
    mazanina The actual image dimensions are 60 cm x 80cm and has a reduced size 3 cm x 4 cm. At what scale the image was reduced?
  3. Cableway
    cable-car Cableway has a length of 1800 m. The horizontal distance between the upper and lower cable car station is 1600 m. Calculate how much meters altitude is higher upper station than the base station.
  4. Cruise liner
    parnik_1 Cruise liner runs along the river between points A and B. The journey downstream takes 40 minutes 1 hour upriver. The flow rate of the river is 3 km/h. What is the speed of cruise liner?
  5. Regular octagon
    220px-N_uholnik Draw the regular octagon ABCDEFGH inscribed with the circle k (S; r = 2.5 cm). Select point S' so that |SS'| = 4.5 cm. Draw S (S '): ABCDEFGH - A'B'C'D'E'F'G'H'.
  6. Cost reduction
    mp3_1 Two MP3 players whose price was equal to originally have been discounted the first by 20%, the second by 35%. After the price reduction was the difference in their prices 750, - CZK. What was the original price of each of the two players?
  7. Sugar 9
    cukr_6 150 kg of sugar beet yields 24 kg of sugar. From how many tons of sugar beet can be obtained three tons of sugar?
  8. Family parcels
    map_4 In father will he divided the land so that the older son had three bigger part than younger son. Later elder son gave 2.5 ha field to younger and they had both the same. Determine the area of family parcel.
  9. Isosceles trapezoid
    rr_lichobeznik Calculate the circumference and the contents of the isosceles trapezoid if you know the size of the bases is 8 and 12 cm and the size of the arms is 5 cm.
  10. TVs
    tv Production of television sets increased from 3,500 units to 4,200 units. Calculate the percentage of production increase.
  11. Shell of cylinder
    cylinder_4 Calculate the content of shell the 1.6 m height cylinder with a base radius of 0.4 m.
  12. Pyramid Z8–I–6
    pyramida_mo Each brick of pyramid contains one number. Whenever possible, the number in each brick is lowest common multiple of two numbers of bricks lying directly above it. That number may be in the lowest brick? Determine all possibilities.
  13. Is right triangle
    triangle_1111_4 Decide if the triangle XYZ is rectangular: x = 4 m, y = 6 m, z = 4 m
  14. Two numbers
    fractal_6 The sum of the two numbers is 1. Find both numbers if you know that half of the first is equal to one seventh of the second number.
  15. Fuel mileage
    fuel2 You have 3/8 tank of fuel. Estimate fuel consumption @ 6mpg. Estimate speed @ 50mph. Your fuel tank holds 200 gals. Figure out fuel mileage.
  16. Roses 2
    ruze Aunt Rose went to the flower shop to buy a bouquet with three roses. The flower shop had white, yellow and red roses. How many different flowers bouquet can a flower make for Aunt Rose create? Write all the bouquet options.
  17. Rabbits 3
    rabbits Viju has 40 chickens and rabbits. If in all there are 90 legs. How many rabbits are there with Viju?
  18. Right triangle ABC
    right_triangle_2 Calculate the perimeter and area of a right triangle ABC, if you know the length of legs 4 cm 5.5 cm and 6.8 cm is hypotenuse.
  19. Diagonals of diamond
    kosostvorec_4 Find the area and circumference of the diamond ABCD with 15m and 11m diagonals.
  20. Percentages
    percents2 Calculate the percentages to two decimal places: a / 15 min in 4 hours B / 35 cm2 of 12.5 dm2 c / 2dm2 of 400 cm2 D / 0.2 liters from 2.2 liters

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