Examples for 8th grade - page 78

  1. 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.
  2. Four ropes
    vysilac TV transmitter is anchored at a height of 44 meters by four ropes. Each rope is attached at a distance of 55 meters from the heel of the TV transmitter. Calculate how many meters of rope were used in the construction of the transmitter. At each attachment.
  3. 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?
  4. Line segment
    lines_5 Cut a line segment of 15 cm into two line segments so that their lengths are in ratio 2:1. What length will each have?
  5. Cuboid - ratios
    kvader11 The sizes of the edges of the cuboid are in the ratio 2: 3: 5. The smallest wall have area 54 cm2. Calculate the surface area and volume of this cuboid.
  6. Unknown number
    nums Identify unknown number which 1/5 is 40 greater than one tenth of that number.
  7. Pumps
    pumps Five pumps pumped 1,800 hl of water for 3 hours. How many hectoliters of water pump same two powerful pumps for six hours?
  8. 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.
  9. 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.
  10. Is right triangle
    triangle_1111_4 Decide if the triangle XYZ is rectangular: x = 4 m, y = 6 m, z = 4 m
  11. Glass
    sklenice_1 Trader ordered from the manufacturer 200 cut glass. The manufacturer confirmed the order that the glass in boxes sent a kit containing either four or six glasses. Total sent 41 boxes. a) How many boxes will contain only 4 glasses? b) How many boxes will co
  12. 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?
  13. Combinations of sweaters
    sveter I have 4 sweaters two are white, 1 red and 1 green. How many ways can this done?
  14. Rabbits 3
    rabbits Viju has 40 chickens and rabbits. If in all there are 90 legs. How many rabbits are there with Viju?
  15. 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
  16. TVs
    tv Production of television sets increased from 3,500 units to 4,200 units. Calculate the percentage of production increase.
  17. Tickets
    stadion_1 On the football tournament ticket cost 45 Kc for standing and 120kč for sitting. Sitting spectators was 1/3 more than standing. The organizers collected a total 12 300 Kc. How many seated and standing seats (spectators)?
  18. Shell of cylinder
    cylinder_4 Calculate the content of shell the 1.6 m height cylinder with a base radius of 0.4 m.
  19. 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.
  20. 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?

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