Examples for 8th grade - page 52

  1. Leg
    tetris Determine the area of a trapezoid with bases 60 and 37 and height is 3 shorter than the its leg.
  2. Sales vs profit
    Acer+vs+Apple Apple sells 45 percent less computes than the Acer but the profit from their sales is 1.7 times higher than Acer. How many times are Apple computer more expensive than Acer?
  3. Sector
    vysec The perimeter of a circular sector with an angle 2 rad is 53 cm. Determine the radius of the circle from which the sector comes.
  4. Cyclists
    cyclist_3 Cyclist who rides at an average speed 17 km/h travels trip distance 14 min before the cyclist who rides at an average speed 15 km/h. What is the length of this cyclist trip(distance in km)?
  5. Car
    american-cars Car goes from point A to point B at speed 70 km/h and back 76 km/h. If they goes there and back at speed 73 km/h trip would take 19 minutes shorter. What is distance between points A and B?
  6. Road embankment
    nasyp_cesta Road embankment has a cross section shape of an isosceles trapezoid with bases 9 m and 12 m, and 4 m long leg. How many cubic meters of soil is in embankment length of 758 meters?
  7. Road
    route-66 Average climb of the road is given by ratio 1:29. By what angle road average climb?
  8. Divisibility
    dots Determine the smallest integer which divided 8 gives remainder 6 when divided 19 gives remainder 9 and when divided by 11 gives remainder 2.
  9. Climb
    Mazda_RX7_1 On the road sign, which informs the climb is 20%. Car goes 5 km along this road. What is the height difference that car went?
  10. Rotary cone
    cone_2 Rotary cone whose height is equal to the circumference of the base, has a volume 4772 cm3. Calculate the radius of the base circle and height of the cone.
  11. Perpendicular
    slopeplane What is the slope of the perpendicular bisector of line segment AB if A[-9,-8] and B[-8,0]?
  12. Parallelogram
    paralleogram Calculate area of the parallelogram ABCD as shown if |AB| = 45 cm, |BC| = 23 cm and angle BAD = 30°
  13. Rhombus
    rhombus2 Internal angles of rhombus is in ratio 3:6. How many times is the shorter diagonal longer than side of rhombus?
  14. Area 4gon
    4gon Calculate area of 4-gon, two and the two sides are equal and parallel with lengths 7, 15, 7 and 15. Inner angles are 45°, 135°,45°, 135°.
  15. Triangle
    triangle_circle Calculate the area of right triangle ΔABC, if one leg is long 12 and its opposite angle is 31°.
  16. Equator
    around_globe Suppose that tourist went on foot over the Globe equator. How many meters more track made ​​his hat on his head as the shoes on your feet? The radius of the earth is 6378 km and height of the tourist is 1.7 m.
  17. Election mathematics
    statny-znak-sr_1 In elections, 6 political parties received this shares of voters: strana A 69.4 %strana B 11.2 %strana C 10.2 %strana D 7.6 %strana E 1.6 % Calculate what the shares acquired in the parliament, if a quorum is 5%.
  18. Right triangle trigonometrics
    triangle2 Calculate the size of the remaining sides and angles of a right triangle ABC if it is given: b = 10 cm; c = 20 cm; angle alpha = 60° and the angle beta = 30° (use the Pythagorean theorem and functions sine, cosine, tangent, cotangent)
  19. Job task
    clocks2_5 After two hours and 40 minutes the job is finished. Compared to last year we were 40 minutes faster. What is the percentage increase to our performance?
  20. Parallelogram
    kosostvorec_3 Side a of parallelogram is twice longer than side b. Its circumference is 78 dm. Calculate the length of the sides of a parallelogram.

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.