# Examples for 8th grade - page 10

- Strange x

For what x is true ?? - Metallurgical enterprise

Metallurgical company daily produces 873 tons of cast iron. How many tons of coke it burns to melt cast iron when 17 tons of cast consumes 13 tons of coke? - Trapezoid MO-5-Z8

ABCD is a trapezoid that lime segment CE divided into a triangle and parallelogram as shown. Point F is the midpoint of CE, DF line passes through the center of the segment BE and the area of the triangle CDE is 3 cm^{2.}Determine the area of the trapezoid A - Tissues

The store got three kinds of tissues - 132 children, 156 women and 204 men. Tissues each species were packed into boxes after the number of pieces the same for all three types (and greatest). Determine the number, if you know that every box has more than 6 - Two doctors

Doctor A will determine the correct diagnosis with a probability 80% and doctor B with a probability 72%. Calculate probability of correct diagnosis if patient is diagnosed by both doctors. - Coffee

Coffee from the machine in the cup cost 25 cents. Coffee is 20 cents more expensive than the cup. How much is the cup? - Blueberries

Marie earns 1.8 liters of blueberries for 1.2 hours, Peter 2.6 liters for 1.2 hours. How long have earns together one liter? - The bridge

Across the circle lakepasses through its center bridge over the lake. At three different locations on the lake shore are three fishermen A, B, C. Which of fishermen see the bridge under the largest angle? - Cube

The cube weighs 18 kg. How weight is cube of the same material, if its dimensions are 3-times smaller? - Eiffel Tower

Eiffel Tower in Paris is 300 meters high, is made of steel. Its weight is 8000 tons. How tall is the tower model made of the same material, if it weigh is 4.8 kg? - Mountain railway

Height difference between points A, B of railway line is 38.5 meters, their horizontal distance is 3.5 km. Determine average climb in permille up the track. - 30-60-90

The longer leg of a 30°-60°-90° triangle measures 7. What is the length of the shorter leg? - Garden

Area of square garden is 6/7 of triangle garden with sides 96 m, 60 m and 60 m. How many meters of fencing need to fence a square garden? - Square and circles

Square with sides 82 km is circumscribed and inscribed with circles. Determine the radiuses of both circles. - Coins

On coins found was stated that from the year 87 BC. It is right? - The dice

What is the probability of events that if we throw a dice is rolled less than 6? - Rhombus

Calculate the perimeter and area of rhombus whose diagonals are 15 cm and 27 cm long. - Crown

Siblings collect a 2-crowns and 5-crowns. Together have 80 coins with a total of value 310 crowns. How many saved two-crowns and how many five-crowns? - Bus vs. train

Bus started from point A 15 minutes before the train started from the same place. The bus went an average speed of 49 km/h, train 66 km/h. To point B train and bus arrived simultaneously. Calculate time of train journey, if train and bus travelled the. - Olympics

In how many ways can be placed 6 athletes on the podium at the Olympics? Depend on the color of the metal.

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