# Examples for 8th grade - page 32

1. Paul and Honza Honza went to chat on a bike without a break 4.0 hours. Paul the same way without breaks 50 minutes longer. The difference between the speeds of the two boys was the one kilometer per hour. How fast was Paul, if you know that the speed of the boys did not.
2. Center traverse It is true that the middle traverse bisects the triangle?
3. Arc The length of the circle is 41 amd arc length of the circle 9. What is the magnitude of the angle of this arc?
4. Enterprise and wages The enterprise operates a total 162 workers and their average salary is M dollars. If the company has hire an additional 18 employees whose average wage would be the S dollars, would reduce the overall average salary in the company of 3.6%. Calculate the
5. Two workers Two workers carry will do certain work for 12 days. After 8 days of working was one removed, and then the other finished the job alone in 10 days. For how many days would do this work alone each worker?
6. ISO trapezoid v2 bases of Isosceles trapezoid measured 12 cm and 5 cm and its perimeter is 21 cm. What is the are of a trapezoid?
7. Base Compute base of an isosceles triangle, with the arm a=20 cm and a height above the base h=10 cm.
8. Raffle How many raffle tickets must be purchased by Peter in raffle with issued 200 tickets if he wants to be sure win at least 3 price? In the raffle draws 30 prices.
9. Construct 1 Construct a triangle ABC, a = 7 cm, b = 9 cm with right angle at C, construct the axis of all three sides. Measure the length of side c (and write).
10. Diagonal Diagonal of the rectangle has length 46.4 cm. Angle between diagonal and londer sife of rectangle is 22°. Calculate area of the rectangle.
11. Swimming pool 4 The pool shaped cuboid measuring 12.5 m × 640 cm at the bottom is 960hl water. To what height in meters reaches the water level?
12. Square prism Calculate the volume of a square prism of high 2 dm wherein the base is: rectangle with sides 17 cm and 1.3 dm
13. Vectors Vector a has coordinates (8; 10) and vector b has coordinates (0; 17). If the vector c = b - a, what is the magnitude of the vector c?
14. TV diagonal Diagonal TV is 0.56 m long, how big the television sreen is if the aspect ratio is 16:9?
15. Invitations For every 5 minutes writes Dana 10 invitations, while Anna 14 invitations. How long will write together 120 invitations?
16. Sales off If a sweater sells for \$ 19 after a 5% markdown, what was its original price?
17. Summerjob Albert, Beny, Cyril and Dan worked on summerjob. From the total revenue Albert received 2/5, Beny 1/6 , 3/10 Cyril and Dan the rest which is 324 euros. How many euros earned every one of them?
18. Chalet The children were on a school trip to the mountain . One third of the journey went by the train and continue by bus. When you get off the bus, they remained a third of the distance they traveled by bus. What part of journey children went by the bus (wrote
19. Circumference - a simple What is the ratio of the circumference of any circle and its diameter? Write the result as a real number rounded to 2 decimal places.
20. Train from Brno First train started from Brno at 8 am at 60 km per hour. Second train started from Opava at 7 o'clock at the speed of 40 kilometers per hour. In how many hours and how far from cities trains meet when the distance of cities is 200 kilometers.

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