Examples for 9th grade - page 16

  1. Shooter
    terc_1 The shooter fired to a target from distance 9 m The individual concentric circle of targets have a radius increments 1 cm (25 points) by 1 point. Shot was shifted by 16'(angle degree minutes). How many points should win his shot?
  2. Drunk man
    drunk-man Drunkman has 2.1‰ of alcohol in the blood. How many grams of alcohol has in blood, if he have 6 kg of blood?
  3. 3y inflation
    bread Price of the medicament rise in the first year by 8%, the second year fell by 4% and in the third year increased by 10%. Calculate the average annual increase in price of the medicament.
  4. Black building
    talapka_cierna_stavba Jordan built building with a rectangular shape 5 m × 5.1 m. Calculate how much percent exceeded the limit 25 m2 for small building. Building not built in accordance with the law is called "black building". Calculate the angle that the walls were clenching
  5. XY triangle
    triangle Determine area of triangle given by line -7x+7y+63=0 and coordinate axes x and y.
  6. Lid
    drywell What is the weight of concrete cover (lid) to round shape well with a diameter 1.3 m, if the thickness of the cover is 15 cm? 1 m3 of concrete weighs 2190 kg.
  7. Pumps
    water_pump Pump that draws water at velocity 3.5 liters per second water from a construction trench take 35 minutes. a) Find out how many minutes the water would run out of the trench pump that draws 7.4 liters of water per second. b) What is the pumping velocity wo
  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. Spherical segment
    circular_segment_1 Spherical segment with height h=8 has a volume V=294. Calculate the radius of the sphere of which is cut this segment.
  10. Trapezoid - diagonal
    licho Trapezoid has a length of diagonal AC corssed with diagonal BD in the ratio 2:1. The triangle created by points A, cross point of diagonals S and point D has area 164 cm2. What is the area of the trapezoid?
  11. Mystery of stereometrie
    Tetrahedron Two regular tetrahedrons have surfaces 48 cm2 and 108 cm2. In what ratio is their volumes? Write as a fraction and as a decimal rounded to 4 decimal places.
  12. Road
    route-66 Average climb of the road is given by ratio 1:29. By what angle road average climb?
  13. Slope of the pool
    swimming_pool Calculate slope (rise:run) of the bottom of swimming pool long 40 m. Water depth at beginning of pool is 1.15 m (for children) and depth at end is 1.92 m (for swimmers). Slope express as percentage and as angle in degrees.
  14. Elevation
    horizon_diagram What must be the elevation of an observer in order that he may be able to see an object on the earth 814 km away? Assume the earth to be a smooth sphere with radius 6378.1 km.
  15. Sea
    ship How far can you see from the ship's mast, whose peak is at 11 meters above sea level? (Earth's radius is 6370 km).
  16. Pit
    ihlan_zrezany Pit has shape of a truncated pyramid with rectangular bases and is 2.8 m deep. The length and width of the pit is the top 3 × 1.5 m bottom 1 m × 0.5 m. To paint one square meter of pit we use 0.3 l of green colour. How many liters of paint is needed when w
  17. Amazing number
    numbers4 An amazing number is name for such even number, the decomposition product of prime numbers has exactly three not necessarily different factors and the sum of all its divisors is equal to twice that number. Find all amazing numbers.
  18. Circle in rhombus
    circle_rhombus In the rhombus is inscribed circle. Contact points of touch divide the sides to parts of length 18 cm and 17 cm. Calculate the circle area.
  19. Car factory
    VW_logo Carmaker now produce 4 cars a day more than last year, so the production of 413448 cars will save just one full working day. How many working days needed to manufacture 413448 cars last year?
  20. AVG of INT
    seq_moon What is the average of the integers from 7 throuht 15 inclusive?

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.