Examples for 8th grade - page 40

  1. Equations
    p1110617 Solve following system of equations: 6(x+7)+4(y-5)=12 2(x+y)-3(-2x+4y)=-44
  2. Freight train
    Freight_train The train carries 525 tons of limestone in 29 wagons. Wagons are 15 tonne and 20 tons. How many is 15 ton and how many is 20 ton wagons?
  3. A three-digit numbers
    clocks_1 Determine the total number of positive three-digit numbers that contain a digit 1.
  4. Acute angles
    angles_meter Sizes of acute angles in the right-angled triangle are in the ratio 1: 6. What is size of the larger of them?
  5. Diameter
    diameter_circle If the endpoints of a diameter of a circle are A(10, -5) and B (8, 7), what is the radius of the circle?
  6. Car
    city The driver of a car is to get to 378 km distant city. From atlas found that 99 km will have to pass through the cities at average speed 48 km/h. Remainder of the journey pass outside the cities at average speed 117 km/h. Calculate how many hours it will ta
  7. Roller
    cestnyvalec Roller has a diameter of 0.97 m and a width 169 cm. How many m2 of road level when he turns 68-times?
  8. Rectangle
    golden-rectangle-ratio Calculate the length of the side FL and diagonal JL of rectangle JFLB when given: |BL| = 33 cm and angle ∠ JFB = 32 degrees.
  9. President
    bush_president The country has 5.9 million citizens which 2.24 million are voters. Turnout was 39.9%. President R. F. was elected from 19 candidates for president and won with 28% of votes. Calculate what percentage of the country's citizens voted R.F. as president of
  10. Driving school
    bmw-autoskola Driving final exam involving 17 attendants. The exam consists of three parts. 4 fails at test (quiz) and 3 students fails on car skills test on playground (slalom between the cone). The practical part of the test - driving in town in the real traffic - al
  11. Louvers
    zaluzie The company charges for office equipment louvers total 244 Eur. From the delivery bill is obvious that the louvers are 73 Eur expensive than their installation. What percentage of the total charged is the installation of louvers?
  12. n-gon
    x-gon What is the side length of the regular 5-gon inscribed in a circle of radius 11 cm?
  13. Tank
    barrel_1 In the middle of a cylindrical tank with a bottom diameter 350 cm is standing rod which is 31 cm above the water surface. If we bank rod its end reach surface of the water just by the tank wall. How deep is the tank?
  14. Monty Hall
    Monty_open_door Suppose you're on a game show, and you're given the choice of three doors: Behind one door is a car; behind the others, goats. You pick a door, say No. 1, and the host, who knows what's behind the doors, opens another door, say No. 3, which has a goat. W
  15. Tape
    mg Video is 250% more expensive than tape recorder. How many percent is tape recorder less expensive than video?
  16. Free fall
    volny_pad Stephen fall from height 5 m. Calculate the speed he hit the ground when falling with acceleration g = 9.81 m/s2
  17. Pipe
    1pipes How long is the pipe with an outside diameter of 0.55 m if his coloring consumed 43 kg of color. 1 kg of color coverage is 10 m2.
  18. Euler problem
    euler Someone buys a 720 tolars towels. If it was for the same money of 6 more towels, it would be 6 tolars cheaper each. How many were towels?
  19. Rotating cone II
    cone Calculate area of surface of rotating cone with base radius r=7 cm and height h=17 cm.
  20. Circle and angle
    arc What is the length of the arc of a circle with radius r = 138 cm with cental angle 2.07 rad?

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