- 7th grade (12y) - math problems

Number of problems found: 2784

  • Rotating cone II
    cone Calculate area of surface of rotating cone with base radius r=19 cm and height h=9 cm.
  • Average
    gaussian The average of 5 numbers is 108. What is its sum?
  • Bulbs
    bulbs In the box are 6 bulbs with power 75 W, 14 bulbs with power 40 W and 15 with 60 W. Calculate probability that a randomly selected bulb is:
  • Rectangles
    rectangles How many rectangles with area 8713 cm2 whose sides are natural numbers are?
  • Guess number
    divide With what number should be divided, number 9727 to be reduced by 70%?
  • Secret number
    secret_num Determine the secret number n, which reversed decrease by 16.4 if the number increase by 16.4.
  • Earth parallel
    parallels Earth's radius is 6370 km long. Calculate the length parallel of latitude 50°.
  • Tree trunk
    kmen Calculate the average tree trunk with a circumference of 149 cm.
  • Clock
    clock How long is the trajectory of the second hand of hours for day, if it is 15 mm long?
  • Seedcake
    pletenky Seedcake costs 44 cents. How many minimum seedcakes we must buy that we can pay in cash only whole euros?
  • Equilateral triangle
    unilateral_triangle Calculate the side of an equilateral triangle if its area is 892 mm2.
  • Circle
    circle How big is an area of a circle if its circumference is 51.2 cm?
  • Truncated cone
    truncated_cone Calculate the volume of a truncated cone with base radiuses r1=13 cm, r2 = 10 cm and height v = 8 cm.
  • Copper sheet
    cuplech The copper plate has a length of 1 m, width 94 cm and weighs 9 kg. What is the plate thickness, if 1 m3 weighs 8715 kg?
  • Cylinder
    valec Calculate the dimensions of rotating cylindrical containers with volume 2 l if the container's height is equal to the base's diameter.
  • Car range
    skoda_limousine Kia has an average diesel consumption of 3.9 liters per 100 kilometers. What is the range of the car for 179 euros if fuel costs 1.3 EUR/liter, if the tank has a volume of 55 liters?
  • Fuel consumption
    1car Škoda car has an average diesel consumption of 5.9 liters per 100 kilometers. What is the car range for a full tank of volume 70 liters?
  • Forest nursery
    lesna_skolka In Forest nursery plant one pine to 1.9 m2. Calculate how many plants are planting in area 362 acres.
  • Pipe
    trubka_ocel Steel pipe has a length 2.5 meters. About how many decimetres is 1/3 less than 4/8 of this steel pipe?
  • Flags
    vlajka_cz How many different flags can be made from colors red, yellow, blue, green, white to consist of three different colors?

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