Examples for 8th grade - page 43

  1. Slope
    lines.JPG Calculate the slope of a line that intersects points (38,-23) and (-93,5).
  2. Two wine
    wines In 2:1 mix wine solution cost 4.1 USD. In 1:2 mix wine solution cost 4.5 USD. How much cost liter of each wine?
  3. Concentric circles
    chord_2 In the circle with diameter 17 cm is constructed chord 12 cm long. Calculate the radius of a concentric circle that touches this chord.
  4. 6 regular polygon
    hexagon_2 It is given 6 side regular polygon whose side is 5 cm. Calculate its content area. Compare how many more cm2 (square centimeters) has a circle in which is inscribed the 6-gon.
  5. Annulus
    medzikruzie.JPG Two concentric circles form an annulus of width 10 cm. The radius of the smaller circle is 20 cm. Calculate the content area of annulus.
  6. Lie/do not lie
    lines_and_points The function is given by the rule f(x) = -x-12. Determine whether point D[-4; 2] lies on this function. Solve graphically or numerically and give reasons for the your answer.
  7. Two trains
    two-trains Two trains go at each other. First at speed 40 km/h and the second at speed 60 km/h. At what distance will be 30 minutes before they will meet?
  8. Prism
    prism The volume of tetrahedral prism is 2.43 m3. Base of prism is a parallelogram in which a side 2,5dm and height ha = 18cm. Calculate the height of the prism.
  9. Map scale
    garden_5 Garden has on plan on a scale of 1: 150 width 22 cm and length 35 cm. What is the real area of the garden?
  10. Powers
    math_fun Is true for any number a,b,c,d equality:? ?
  11. Mixing
    FMCG If we mix 5 kg of goods of one kind and 3 kg second one, resulting mixture cost 16.50 EUR/kg. If these quantities are mixed in reverse - first three kilograms and 5 kilograms second cost of mixture is 18.50 EUR/kg. What is the price of one kg of goods of.
  12. Water reservoir
    nadrz_3 The water reservoir is filled with one pump for 4 days by the second one for 9 days. Outlet can drain tank in 12 days. How long take fill the reservoir if both pumps are running and not closed outlet channel.
  13. Thales
    circles_1 Calculate the length of the Thales' circle described to right triangle with hypotenuse 44 cm.
  14. Quadrilateral
    diamond_2 In the square ABCD point P is in the middle of the DC side and point Q in the middle pages AD. If the area of quadrilateral BQPC is 96 cm2, what is the area of ABCD?
  15. Garage
    garaz2 There are two laths in the garage opposite one another: one 2 meters long and the second 3 meters long. They fall against each other and stay against the opposite walls of the garage and both laths cross 70 cm above the garage floor. How wide is the garag
  16. Decomposition
    prime_factorization Make decomposition using prime numbers of number 355. Result write as prime factors (all, even multiple)
  17. Chord MN
    lyra_tetiva Chord MN of circle has distance from the center circle S 118 cm. Angle MSN is 41°. Determine the radius of the circle.
  18. Bakery
    bread_1 How heavy must prepare bread at a bakery if lose during baking 14% of water and after baking must have 1.6 kg? (Calculate to the nearest gram)
  19. Cuboid - simple
    cuboid_6 Calculate the surface area and volume of a cuboid if a = 8 cm, b = 14 cm and c = 6 cm.
  20. Deposit 3
    interest_money After a year had Martin on bank account € 1764. What was the interest rate when the initial deposit was € 1581?

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