# Examples for 8th grade - page 57

- The body

The body on the figure consists of cubes with an edge length 10 cm. What surface has this body? - Family and age ratios

Age of father and son are in the ratio 10:3; age of father and daughter are in the ratio 5:2. How old is father and son, if daughter is 20 years old? In what ratio is age sister and brother? - Parallelogram

The perimeter of the parallelogram is 202 cm. The length of one side is 1.2-times longer than the length of the shorter side. What is the length of sides of a parallelogram? - Trousers

Jarek bought new trousers, but the trousers were too long. Their length was in the ratio 5: 8 to Jarek height. Mother his trousers cut by 4 cm, thus the original ratio decreased by 4%. Determine Jarek's high. - Sinus

Determine the smallest integer p for which the equation 5 sin x = p has no solution. - Pedestrian up-down hill

Pedestrian goes for a walk first at plane at 4 km/h, then uphill 3 km/h. Then it is in the middle of the route, turns back and goes downhill at speed 6 km/h. Total walk was 6 hours. How many kilometers went pedestrian? - Pigs

Pigs are feed by beet.Beet feed containing 12% dry solids, which is 0.66% of digestible crude protein. How much beet must beconsumed in one month (30 days), if the weight of digestible crude protein contained in a daily dose of beet was 0.688 kg? - Aircrafts

Above the town hall tower flew the plane with constant speed 508 km/h and 15 minutes later the second plane at speed of 651 km/h. How long and how far from the town hall will be aircrafts caught up? - Inscribed rectangle

The circle area is 184. Determine the area of inscribed rectangle with one side 10 long. - ISO trapezium

Calculate area of isosceles trapezoid with base 53 long, leg 43 long and with the angle between the base and leg 70 degrees. - Ethnicity

Share of ethnicity XY is 10%, which is 1/9 more than in the prewar period. What was the share of that ethnicity in the pre-war period? - Circle section

Equilateral triangle with side 50 is inscribed circle section whose center is in one of the vertices of the triangle and the arc touches the opposite side. Calculate: a) the length of the arc b) the ratio betewwn the circumference to the circle sector. - Round table

Round table with diameter d = 95 cm is coated by square tablecloth with a side length 122 cm. About how many cm is higher center of tablecloth than its cornes? - Similarity coefficient

The ratio of similarity of two equilateral triangles is 3.9 (ie 39:10). The length of the side of smaller triangle is 3 cm. Calculate the perimeter and area of the larger triangle. - Icerink

Rectangular rink with dimensions of 79.5 m and 529 dm must be covered with a layer of ice 4.5 cm thick. How many liters of water is necessary for the formation of ice when the volume of ice is 10.9% greater than the volume of water. - n-gon II

What is the side length of the regular 9-gon circumscribed circle of radius 13 cm? - Addends

Number 389 divide into the two addends that the first was 6 greater than 60% of the second. Determine these addends. - Prism

Right angle prism, whose base is right triangle with leg a = 3 cm and hypotenuse c = 5 cm has same volume as a cube with an edge length of 1 dm. a) Determine the height of the prism b) Calculate the surface of the prism c) What percentage of the cube' - Sines

In ▵ ABC, if sin(α)=0.5 and sin(β)=0.1 calculate sin(γ) - Steamship

Between the two ports on the river is going steamship. The journey there and back takes 14:49. Downstream steamship traveling at 21 km/h, upstream 9 km/h. What is the distance between the ports?

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