Examples for 8th grade - page 77

  1. Unknown number
    nums Identify unknown number which 1/5 is 40 greater than one tenth of that number.
  2. Greenhouse
    foliovnik Garden plastic greenhouse is shaped half cylinder with a diameter of 6 m and base length 20 m. At least how many m2 of plastic is need to its cover?
  3. Three figures - numbers
    numbers34 The sum of three numbers, if each is 10% larger than the previous one, is 662. Determine the figures.
  4. Sale off 2
    sale A pair of of blues jeans went on sale. After a 30% reduction the pants cost $35. How much did the jeans cost before the price reduction?
  5. Candy
    bonbons_5 The price for 1kg of more expensive candy is 125 CZK. The price for 1kg of cheaper candy is 100 CZK. We make two different blends of candy. And now. The second blend contains 2kg of more expensive candy and several kg of cheaper candy. The price per 1 kg o
  6. Family
    sediny Mom is 39 years old. Karl is eight years and Paul 4 years. For many years mother would old just like two children together?
  7. 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?
  8. 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?
  9. 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?
  10. 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.
  11. 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.
  12. 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.
  13. 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.
  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. 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?
  16. Is right triangle
    triangle_1111_4 Decide if the triangle XYZ is rectangular: x = 4 m, y = 6 m, z = 4 m
  17. 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?
  18. Contestants
    avg_1 In the competition it was possible to get 0-5 points. In fact, 5 contestants of the 15 best contestants has earned 5 points or 4 points (which have won 10 contestants). The number of contestants who earned 3 points was the same as the number of contestan
  19. Shell of cylinder
    cylinder_4 Calculate the content of shell the 1.6 m height cylinder with a base radius of 0.4 m.
  20. 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.

Do you have interesting mathematical example 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 e-mail correctly and check whether you don't have a full mailbox.