Examples for 8th grade

  1. Height
    equilateral_triangle Calculate height of the equilateral triangle if its perimeter is 8?
  2. Tanker
    oil-tanker An oil tanker can be emptied by the first pump in 4.9 hours. Second pump can empty an tanker in 8 hours. If the first pump started at 4:00 and second 1.4 hour later, at what time will the tanker be empty?
  3. Hostel
    student Students are accommodated in 22 rooms. Rooms were 4 and 6 bed. How many rooms in which type occupied 106 children there?
  4. Squaring the Circle
    SquareCircle Calculating side of the square with the same area as the circle of radius 18.
  5. Circumscribing
    thales Determine the radius of the circumscribed circle to the right triangle with legs 9 cm and 6 cm.
  6. 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.
  7. Clock
    hodiny How many times a day hands on a clock overlap?
  8. AVG of INT
    seq_moon What is the average of the integers from 9 throuht 52 inclusive?
  9. Climb
    Mazda_RX7_1 On the road sign, which informs the climb is 8.7%. Car goes 5 km along this road. What is the height difference that car went?
  10. Slope
    slope What is the slope of the line defined by the equation -2x +3y = -1 ?
  11. Cylinder - h
    cylinder_2 Cylinder volume is 215 cm3. Base radius is 2 cm. Calculate the height of the cylinder.
  12. Sines
    sines In ▵ ABC, if sin(α)=0.5 and sin(β)=0.6 calculate sin(γ)
  13. OK circle
    circles2 Calculate the radius (circumradius) of the circle described right triangle with hypotenuse long 33 and one cathetus long 17.
  14. ABS
    sphere_nice What is the value of ? ?
  15. R Trapezium
    Trapezium_example Rectangular trapezium has bases 12 and 5 and area 84 cm2. What is its perimeter?
  16. Sea water
    sea_1 Seawater contains about 4.3% salt. How many dm3 of distilled water we must pour into 5 dm3 of sea water to get water with 1.8% salt?
  17. Steamship
    parnik Between the two ports on the river is going steamship. The journey there and back takes 8:42. Downstream steamship traveling at 20 km/h, upstream 9 km/h. What is the distance between the ports?
  18. Workers
    workers Two workers fulfill a certain task when working together for 5 days, the first if he worked himself done work in 13 days. How many days will do whole job a second worker?
  19. 4s pyramid
    pyramid_regular Regular tetrahedral pyramid has a base edge a=17 and collaterally edge length b=32. What is its height?
  20. Reflector
    lamp Circular reflector throws light cone with a vertex angle 49° and is on 33 m height tower. The axis of the light beam has with the axis of the tower angle 30°. What is the maximum length of the illuminated horizontal plane?

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