Examples for 8th grade

Number of problems found: 2980

  • Canopy
    cone-roof Mr Peter has a metal roof cone shape with a height of 127 cm and radius 130 cm over well. He needs to paint the roof with anticorrosion. How many kg of color must he buy if the manufacturer specifies the consumption of 1 kg to 3.3 m2?
  • Coffee shop
    coffee-beans To the coffee shop brought 2 types of coffee totally 50 kg. The first type was CZK 220 per kilogram, coffee second type 300 CZK per 1 kg. For all the coffee trader earned CZK 12,000. How many kilograms of coffee of first type and how many kilograms of cof
  • Similarity coefficient
    triangles In the triangle TMA the length of the sides is t = 5cm, m = 3.5cm, a = 6.2cm. Another similar triangle has side lengths of 6.65 cm, 11.78 cm, 9.5 cm. Determine the similarity coefficient of these triangles and assign similar sides to each other.
  • Flowerbed
    tulipany Family cultivated tulips on a square flower bed of 6 meters. Later they added the square terrace with a side of 7 meters to their house. One vertex of the terrace lay exactly in the middle of a tulip bed, and one side of the terrace divided the side of th
  • Intelligence test
    test Paľo, Jano, Karol, and Rišo were doing an intelligence test. Palo correctly answered half of the questions plus 7 questions, Jano to a third plus 18 questions, Karol to a quarter plus 21 questions and Risho to a fifth plus 25 questions. After the test, Ka
  • Sweets
    Caramelos We want to prepare 5 kg of sweets for 150 CZK. We will mix cheaper candy: 1 kg for 120 CZK and more expensive candy: 1 kg per 240 CZK. How much of this two types of candy is necessary to prepare this mixture?
  • Ethernet cable
    EthernetCable Charles and George are passionate gamers and live in houses that are exactly opposite each other across the street, so they can see each other through the windows. They decided that their computers will connect the telephone cable in order to play games t
  • Z9-I-4
    numbers_30 Kate thought a five-digit integer. She wrote the sum of this number and its half at the first line to the workbook. On the second line wrote a total of this number and its one fifth. On the third row, she wrote a sum of this number and its one nines. Fina
  • Bronze, tin and copper
    zvon Bronze is an alloy of tin and copper. An alloy of 10% tin and 90% copper is Gunmetal. If it contains 20% tin and 80% copper, it is bell metal. How many tons of molten bell metal and how many tons of copper is needed to make 100 tons of Gunmetal?
  • Minimum surface
    cuboid_20 Find the length, breadth, and height of the cuboid-shaped box with a minimum surface area, into which 50 cuboid-shaped blocks, each with length, breadth, and height equal to 4 cm, 3 cm, and 2 cm respectively, can be packed.
  • Water channel
    trapezium_prism_2 The cross section of the water channel is a trapezoid. The width of the bottom is 19.7 m, the water surface width is 28.5 m, the side walls have a slope of 67°30' and 61°15'. Calculate how much water flows through the channel in 5 minutes if the water flo
  • Helmet
    Clock0400_7 Nowadays cycling better results could be obtained not only due to rider physical preparation but also thanks to using updated technologies. One of the essential parts of the rider´s equipment is his or her helmet. While most bikers wear a helmet mainly to
  • Wheat
    field_1 The rectangle shaped field with dimensions 1268 m and 745 m harvested last year was 4959 q wheat. (1 q = 1 quintal = 100 kg). During the year, it was necessary to fix the pipe and therefore did kick wide 4 m parallel to the side of the field 745 m, where
  • Company car
    fuel Ms. Vaňková has a company car equipped with a multifunction indicator, on which she can monitor the average petrol consumption during individual rides. During the first ride, mostly in city traffic, it traveled 20.5 km, with an average consumption of 7.8L
  • Profitable bank deposit 2012
    eurocoins Calculate the value of what money lose creditor with a deposit € 9500 for 4 years if the entire duration is interest 2.6% p.a. and tax on interest is 19%. Annual inflation is 3.7% (Calculate what you will lose if you leave money lying idle at negative int
  • Pet store
    fish In a pet store, they are selling out the fish from one aquarium. Ondra wanted half of all fish, but they don't wish cut by hal fany fish he got one more than demanded. Matthew wished the remaining half of the fish, but as Andrew got half the fish more tha
  • Overtaking
    dopravni-znacka-zakaz-predjizdeni On the direct road, the passenger car overtakes the slower bus by starting to overtake 20 meters from the bus and after passing it ahead of it again 20 meters away. The car overtakes at a steady speed of 72 km/h, the bus goes at a steady speed of 54 km/h.
  • Mr. John
    jabka Mr. John wants to buy winter apples Spartan. There are two ways to buy: 1) buy apples at the marketplace, where 1 kg costs 15 CZK. 2) Bring the car to the agricultural farm, where the apples are sold after 9 CZK per kilogram. However, he must pay CZK 150
  • Candies
    oriesky_3 In the confectionery, the price for 1 kg of pistachio candies cost CZK 360, and the price for 1 kg of hazelnut candies was CZK 280. Mixing these two types of sweets created a box of chocolates. How many grams of pistachios and how many grams of hazelnut c
  • Cone
    cones Circular cone of height 15 cm and volume 5699 cm3 is at one-third of the height (measured from the bottom) cut by a plane parallel to the base. Calculate the radius and circumference of the circular cut.

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