# Grade - examples - page 49

1. Iron fence
One field of iron fence consists of 20 iron rods with square cross-section of 1.5 cm side and a long 1 meter. How much weight a field if the density of iron is 7800 kg/m3.
2. Future of libraries
You know that thanks to the Internet, electronic communications and developing online resources on the Internet annually declining number of traditional readership by 17%. These deal is irreversible evolutionary shift from old books from libraries to immed
3. Racer
The first racer run at a speed 20 m/s and is 750 meters before the finish and ahead 79 meters before second competitor. At what speed must run the second racer to catch first racer at the finish line?
4. Strawberries
Father collects strawberries himself in 4 hours, son in 14 hours. How long will it take them along when dad comes to help son collect strawberries after 3 hours?
5. Granite cube
What is the weight in kg granite cube with an edge of 0.5 m if 1dm3 of granite weight 2600 g?
6. Pyramid
Cuboid ABCDEFGH has dimensions AB 3 cm, BC 4 cm, CG 5 cm. Calculate the volume and surface area of a triangular pyramid ADEC.
7. Square
If the length of the sides of the square we decrease by 25% decrease the content area of 28 cm2. Determine the side length of the original square.
8. Chicken
I threw three chicken for a handful of grains and I noticed that it eat in a ratio of 8:7:6 and two of them grabbed 156 grains. How many grains have fought that chicken?
9. Sawdust
How many cubic centimeters of wood sawdust is created by cut the tree trunk with a diameter of 66 cm and when the gap width is 5 mm?
10. Surface of the cylinder
Calculate the surface area of the cylinder when its volume is 45 l and the perimeter of base is three times of the height.
11. Copper plate
Copper plate length 3.2 m and width 50 cm weighs 55.42 kg. What is the plate thick, if 1 m3 of copper weighs about 8700 kg?
12. Playground
Rectangular playground is fenced with 38 m long netting. Its width is 7 m. Calculate its length.
13. Unions
Calculate how much money per year would go to the treasury of unions if 218 thousand employee join unions with an average net salary of 407 euros and if memberhip in union cost 1% of the net monthly salary.
14. Cuboids in cube
How many cuboids with dimensions of 6 cm, 8 cm and 12 cm can fit into a cube with side 96 centimeters?
15. Painter 3
Dad want to paint wall high 250 cm wide and 230 cm with wallpaper. How many meters must buy wallpaper if wallpaper width is 60 cm?
16. Cube and water
How many liters of water can fit into a cube with an edge length of 0.11 m?
17. Interest
Calculate how much you earn for 10 years 43000 deposit if the interest rate is 1.3% and the interest period is a quarter.
18. Circle sector
Circular sector with a central angle 80 ° has area 1257 cm2. Calculate its radius r.
19. Building
The building I focused at an angle 30°. When I moved 5 m building I focused at an angle 45°. What is the height of the building?
20. Flowerbed 2
Around the square flower bed in a park is sidewalk 2 m wide. The area of ​​this sidewalk is 243 m2. What is the area of the flowerbed?

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