Examples for 9th grade - page 13

  1. Two doctors
    dr_cvach Doctor A will determine the correct diagnosis with a probability 92% and doctor B with a probability 88%. Calculate probability of correct diagnosis if patient is diagnosed by both doctors.
  2. Rectangles
    rectangles How many rectangles with area 3002 cm2 whose sides is natural numbers are?
  3. Motion
    bus_1 From two different locations distant 232 km started against car and bus. The car started at 5:20 with average speed 64 km/h. Bus started at 7:30 with average speed 80 km/h. When they meet? How many kilometers went the bus?
  4. Rotary cone
    cone_2 Rotary cone whose height is equal to the circumference of the base, has a volume 229 cm3. Calculate the radius of the base circle and height of the cone.
  5. 2x cone
    truncated_cone_2 Circular cone height 76 cm was cut plane parallel with base. Volume of these two small cones is the same. Calculate the height of the smaller cone.
  6. Sale
    sale_percent If the product twice price cut by 25%, what percentage was price cut in total?
  7. Cut and cone
    kuzel Calculate the volume of the rotation cone which lateral surface is circle arc with radius 15 cm and central angle 63 degrees.
  8. Circle section
    circle_segment Equilateral triangle with side 34 is inscribed circle section whose center is in one of the vertices of the triangle and the arc touches the opposite side. Calculate: a) the length of the arc b) the ratio betewwn the circumference to the circle sector.
  9. Jewel
    rhombus3 Rhombus-shaped jewel have area of 153 mm2 and the edge in long 13.9 mm. Calculate the size of rhombus acute angle.
  10. 4s pyramid
    pyramid_regular Regular tetrahedral pyramid has a base edge a=17 and collaterally edge length b=32. What is its height?
  11. Parallelogram
    paralleogram Calculate area of the parallelogram ABCD as shown if |AB| = 19 cm, |BC| = 18 cm and angle BAD = 90°
  12. Circle and angle
    arc What is the length of the arc of a circle with radius r = 207 mm with cental angle 5.33 rad?
  13. Trapezoid
    rectangular_trapezoid Are diagonals in a rectangular trapezoid perpendicular and bisect the angles?
  14. Accidents
    nehoda-pomnik The count of accidents in 1995 caused 8780 women which is 8.4%. How many men caused the accidents?
  15. Tetrahedral pyramid
    krychle_3_jehlany Calculate the volume and surface of the regular tetrahedral pyramid if content area of the base is 20 cm2 and deviation angle of the side edges from the plane of the base is 60 degrees.
  16. RT - hypotenuse and altitude
    pravy_trojuholnik Right triangle BTG has hypotenuse g=117 m and altitude to g is 54 m. How long are hypotenuse segments?
  17. Football league
    football In the 5th football league is 10 teams. How many ways can be filled first, second and third place?
  18. Sequence
    arithmetic_seq In the arithmetic sequence is a1=-1, d=4. Which member is equal to the number 203?
  19. Pillar
    sliced_pyramid Calculate volume of pillar shape of a regular tetrahedral truncated pyramid, if his square have sides a = 19, b = 27 and height is h = 48.
  20. Balls
    balls_1 Ping pong balls have a diameter of approximately 4.6 cm. They are sold in boxes of 4 pieces: each box has the shape of a cuboid with a square base. The balls touch the walls of the box. Calculate what portion of the internal volume of the box is filled w

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