Examples for 8th grade

  1. Two cylinders
    sudy Two cylinders are there one with oil and one with an empty oil cylinder has no fixed value assume infinitely. We are pumping out the oil into an empty cylinder having radius =1 cm height=3 cm rate of pumping oil is 9 cubic centimeters per sec and we are p
  2. Two integers
    x-5-x-3-graph Two integers, a and b, have a product of 36. What is the least possible sum of a and b?
  3. 1st drug
    pirule First drug pack has an active ingredient ratio of L1: L2 = 2: 1 Second drug pack have a ratio of active ingredients L1: L2 = 1: 3 In which ratio do we have to mix the two packages so that the ratio of substances L1: L2 = 1: 2?
  4. Construct rhombus
    koso_vpisana Construct rhombus ABCD if given diagonal length | AC | = 8cm, inscribed circle radius r = 1.5cm
  5. Rectangular garden
    rectangle_1 The perimeter of Peter's rectangular garden is 98 meters. The width of the garden is 60% shorter than its length. Find the dimensions of the rectangular garden in meters. Find the garden area in square meters.
  6. Blueberries collecting
    blueberry_1 Marie collects blueberries 2 l in 1 hour. Began collecting at 8.00 pm, Joe collects 1.5 l in 1 hour. Peter 1 l for 1 hr. And they began to gather at 08.30 pm. Together they collect 10 l. At what time will they all have collected?
  7. Two ports
    ship From port A on the river, the steamer started at an average speed of 12 km/h towards port B. Two hours later, another steamer departed from A at an average speed of 20 km/h. Both ships arrived in B at the same time. What is the distance between ports A an
  8. Apple variete
    jablka This year, my uncle harvested 350 kg of apples, including 105 kilograms of Ontario, and the rest is Jonathan. Determine what percentage of the Jonathan apples.
  9. Art school
    skola_1 Every fifth pupil 9A goes to art school. How many percent of pupils in class 9A go to art school?
  10. Eight masons
    time Eight masons will plaster a wall with an area of 1440 m2 in 9 days. They work 8 hours a day. How much area will plaster 6 masons in 4 hours?
  11. Where and when
    cars The truck left Kremnica at 11:00 h at a speed of 60km/h. At 12:30 h, the passenger car started at an average speed of 80km/h. How many kilometers from Kremnica will the passenger car reach truck, and when?
  12. Ice skates
    korcule Ice skates were raised twice, the first time by 25%, the second time by 10%. After the second price, their cost was 82.5 euros. What was the original price of skates?
  13. Parallels and one secant
    lines_parallel_crossing There are two different parallel lines a, b and a line c that intersect the two parallel lines. Draw a circle that touches all lines at the same time.
  14. Flowerbed
    circles We enlarge the circular flower bed, so its radius increased by 3 m. The substrate consumption per enlarged flower bed was (at the same layer height as before magnification) nine times greater than before. Determine the original flowerbed radius.
  15. Six students
    painter Two pupils painted the class in four hours. How long will it take for six pupils?
  16. Mixture of nuts
    vahy2 The mixture of nuts should be prepared from almonds, peanuts and cashew nuts ratio 1: 2: 3 (respectively). The price of almonds is 150 CZK/kg, the price of peanuts is 140 CZK/kg and the price of cashew nuts is 180 CZK/kg. The price of the mixture is deter
  17. The trapezium
    rt_iso_triangle The trapezium is formed by cutting the top of the right-angled isosceles triangle. The base of the trapezium is 10 cm and the top is 5 cm. Find the area of trapezium.
  18. Chocolate
    percent Chocolate, which originally cost 1.5 euros, was increased by 40%. How many euros did it cost?
  19. Blueberries
    blueberry 5 children collect 4 liters of blueberries in 1.5 hours. a) How many minutes do 3 children take 2 liters of blueberries? b) How many liters of blueberries will be taken by 8 children in 3 hours?
  20. Positional energy
    energy What velocity in km/h must a body weighing 60 kg have for its kinetic energy to be the same as its positional energy at the height 50 m?

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