# Examples for 8th grade - page 39

1. Flowerbed Flowerbed has the shape of an isosceles obtuse triangle. Arm has a size 5.5 meters and an angle opposite to the base size is 94°. What is the distance from the base to opposite vertex?
2. Aquarium 6 How high is the water level in the aquarium with a rectangular base 40cm and 50cm if it is filled 0,65hl of water?
3. Parallelogram Parallelogram has sides lengths in the ratio 3: 4 and perimeter 2.8 meters. Determine the lengths of the sides.
4. Coffee Coffee from the machine in the cup cost 28 cents. Coffee is 20 cents more expensive than the cup. How much is the cup?
5. Digits A, B, C For the various digits A, B, C is true: the square root of the BC is equal to the A and sum B+C is equal to A. Calculate A + 2B + 3C. (BC is a two-digit number, not a product).
6. Bevel I have bevel in the ratio 1:6. What is the angle and how do I calculate it?
7. 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.
8. Hall Rectangular hall will have pave by square tiles with a side length 15 cm. The hall has length 18 meters and width 3 m. How many tiles need to buy if 2 percent of the amount is disrupted during the work?
9. Bouquet Gardener tying bouquet of flowers for 8 and none was left. Then he found that he could tying bouquet of 6 flowers and also none was left. How many have gardener flowers (minimum and maximum) if they had between 50 and 100 flowers?
10. Tetrahedral pyramid It is given a regular tetrahedral pyramid with base edge 6 cm and the height of the pyramid 10 cm. Calculate the length of its side edges.
11. Parallelogram +ľ | AB | = 76cm, | BC | = 44cm, angle BAD = 30 °. Find the area of the parallelogram.
12. Comparing powers How many times is number 56 larger than number 46?
13. Cars Cars started at 7:00 AM. From point A car run at 40 km per hour, from B car run 70 km per hour. Between A and B is 250 km long road. When and where will meet (measured from point A)?
14. Base Base of building is circle with diameter 25 m. Calculate the circumference of a circular trench witch diameter is 41 cm wider than the diameter of the base.
15. Slope What is the slope of the line defined by the equation -2x +3y = -1 ?
16. Cylinder The cylinder surface is 922 dm2, its height is equal to the radius of the base. Calculate height of this cylinder.
17. Concentric circles In the circle with diameter 19 cm is constructed chord 9 cm long. Calculate the radius of a concentric circle that touches this chord.
18. Salary Mr. Johnson's had monthly salary 955 USD since the beginning of year. From which month his salary was increased by 52 USD, when in year earned 11824 USD (enter as a number from 1 to 12)?
19. BW-BS balls Adam has a full box of balls that are large or small, black or white. Ratio of large and small balls is 5:3. Within the large balls the ratio of the black to white is 1:2 and between small balls the ratio of the black to white is 1:8 What is the ratio of.
20. Medal Calculate the approximate weight of the gold Olympics medal, if its diameter is 8 cm and a thickness 6 mm. The density of gold find out in the tables or on the Internet.

Do you have an interesting mathematical word problem that you can't solve it? Enter it, and we can try to solve it.

To this e-mail address, we will reply solution; solved examples are also published here. Please enter the e-mail correctly and check whether you don't have a full mailbox.

Please do not submit problems from current active competitions such as Mathematical Olympiad, correspondence seminars etc...