# Examples for 8th grade - page 68

- Annulus

Calculate the area of two circles annulus k_{1}(S, 3 cm) and k_{2}(S, 5 cm). - Pigs

Pigs are feed by beet.Beet feed containing 12% dry solids, which is 0.72% 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 0.912 kg? - Algebrogram

Solve algebrogram: mama+anna=vari How many solutions are? - Cuboid box

How many m^{2}paper is needed for the sticking cuboid box of dimensions 50 cm, 40 cm and 30 cm? To the folds add one-tenth the area. - Testing

Students of high school have 10 points for each good solved task. The wrong answer is deducted by 5 points. After solving 20 tasks, student Michael had 80 points. How many tasks did he solve correctly and how many wrong? - Rectangle 3-4-5

The sides of the rectangle are in a ratio of 3:4. The length of the rectangle diagonal is 20 cm. Calculate the content of the rectangle. - Math heart

Stylized heart shape created from a square with side 5 cm and two semicircles over his sides. Calculate the content area and its circumference. - Copper wire

What is the weight of 1000 m copper wire with a diameter of 5 mm when rezistivity p = 8.8 g / cm^{3}? - Locomotive

Locomotive pulled a train permanent load of 200 kN horizontally along the track of 5km. What work it done? - Right triangles

How many right triangles we can construct from line segments 3,4,5,6,8,10,12,13,15,17 cm long? (Do not forget to the triangle inequality). - Water lake

The length of the lake water is 8 meters width 7 meters and depth 120 centimeters. How many liters of water can fit into the water lake? - Dealer

Dealer sell digital camera for € 474. Thirty percent of the price was his profit. After some time, decreased interest in selling the camera and therefore reduce its sales price by 11 %. How many percent of the new price now is dealer's profit? Round the - Pages of book

Lenka calculated that if every day to read 16 pages of the book, read a book a day earlier than had read only 14 pages a day. How many pages has this book? - Product - quadratic equation

Product of two numbers is 900. If we increase lowest number by 2 then product will increase by 150. Determine both numbers. - Tonic

One package tonic consume Mom 12 weeks and daughter for 14 weeks. 4 weeks they use the same cream together and then only daughter. How many weeks endured tonic to daughter then? - Three friends

The three friends spent 600 KC in a teahouse. Thomas paid twice as much as Paul. Paul a half less than Zdeněk. How many each paid? - Painting

The room is long 50 meters and wide 60dm and 300 cm high. Calculate how much it will cost painting if area of windows and doors is 15% of the total area. One square meter cost 50cents. - Isosceles trapezoid v3

In an isosceles trapezoid ABCD is the size of the angle β = 81° Determine size of angles α, γ and δ. - Hostel

Students are accommodated in 22 rooms. Rooms were 4 and 6 bed. How many rooms in which type occupied 106 children there? - Task of the year

Determine the number of integers from 1 to 10^{6}with ending four digits 2006.

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