Examples for 9th grade - page 50

  1. Bob and Bobek
    bob_a_bobek At 10h 20min runs Bobek from hat at average speed 12 km/h. At what time must run out Bob at speed 18 km/h to catch him 9 kilometers from the hat?
  2. Series
    fib Your task is express the sum of the following arithmetic series for n = 36: S(n) = 11 + 13 + 15 + 17 + ... + 2n+9 + 2n+11
  3. Chord 4
    circles_5 I need to calculate the circumference of a circle, I know the chord length c=19 cm and the distance from the center d=33 cm chord to the circle.
  4. Square circles
    stvorec_kruh Calculate the length of the described and inscribed circle to the square ABCD with a side of 5cm.
  5. Reduce of the volume
    cubes Calculate how many % reduce the volume of the cube is we reduced length of each edge by 10%.
  6. Speedometer
    lotus The speedometer of a car reads 78 km/h. It's accurate to within 4.2% What is the maximum possible error?
  7. Statistics
    lines_globe The sum of all deviations from the arithmetic mean of the numerical sequence 1, 7, 7, 26, 43, 47, 80, 96, 113, 120 is:
  8. Waiting room
    fly In the waiting room are people and flies. Together they have 15 heads and 50 legs (fly has 6 legs). How many people and flies are in the waiting room?
  9. Children
    car_game Less than 20 children is played various games on the yard. They can create a pairs, triso and quartets. How many children were in the yard when Annie came to them?
  10. Line
    lines_1 Write an equation of a line parallel to To 9x + 3y = 8 That Passes Through The Point (-1, -4). Write in form ax+by=c.
  11. Candelas
    sviecky We burned two unequally thick and long candles. Longer burnt for three and a half hours and shorter for five hours. After two hours of burning it was identical. How many times was longer candle longer then shorter?
  12. Siblings
    tri-sourozenci Three siblings had saved up a total of 1,274 CZK. Peter had saved up to 15% more than Jirka and Hanka 10% less than Peter. How much money they saved each one of them?
  13. Double-track
    vlak_1 On double-track express met with a freight train. Express travel at speed 72 km/h, a freight train at speed 36 km/h. After what time period will be from 9 km apart?
  14. Square vs rectangle
    ctverec Square and rectangle have the same area contents. The length of the rectangle is 9 greater and width 6 less than side of the square. Calculate the side of a square.
  15. Gold coin
    gold_munzen Gold coin contains 963 promile pure gold, which is 8.39 g. What is the weight of coin in grams?
  16. ABS
    sphere_nice What is the value of ? ?
  17. Trapezoid 15
    trapezoid3 Area of trapezoid is 266. What value is x if bases b1 is 2x-3, b2 is 2x+1 and height h is x+4
  18. Alcohol 2
    alko Two types of alcohol one 70% and second 61% give 11 liters of 57% alcohol. How many liters of each type are in the mixture?
  19. Parallelogram ABCD
    paralleogram_1 The area of parallelogram ABCD is 41 cm2. Points M and N are the midpoints of the sides AB and BC. What is the area of a quadrilateral MBND?
  20. Surface and volume od cuboid
    kvader Content area of the square base of cuboid is Sp = 36 cm2 and its height 80 mm. Determine its surface area and volume.

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