# Examples for 8th grade - page 17

1. EQL triangle Calculate inradius and circumradius of equilateral triangle with side a=77 cm.
2. Cube wall Surface of first cube wall his 225 mm2. Second cube area is 60% of the surface of the first cube. Determine the length of the edge of the second cube (x).
3. Block Calculate the volume of a cuboid ABCDEFGH if |AB| = 16 cm, |BC| = 19 cm and the angle ∠CDG = 36.9°
4. Truck Truck went for 4 hours and 30 minutes. If truck increase speed by 11 km/h, went same distance in 2 hours. Calculate this distance.
5. Tractors Six tractors plowing the field for 8 days. After two days, two tractors broke down. How many days were prolonged work in the field?
6. Spherical segment Spherical segment with height h=6 has a volume V=134. Calculate the radius of the sphere of which is cut this segment.
7. XY triangle Determine area of triangle given by line 7x+8y-69=0 and coordinate axes x and y.
8. Three workers Three workers A, B, C have to work on a specific task. Workers A and B completed whole task in 14 days, B together with C for 23 days, A together with C for 13 days. How long it would take to complete the task every one of them alone? How long it would.
9. Heron backlaw Calculate missing side in a triangle with sides 17 and 34 and area 275.
10. Steamship Between the two ports on the river is going steamship. The journey there and back takes 8:42. Downstream steamship traveling at 20 km/h, upstream 9 km/h. What is the distance between the ports?
11. Blueberries Marie earns 3 liters of blueberries for 3.4 hours, Peter 2.4 liters for 2.9 hours. How long have earns together one liter?
12. Coin and die Flip a coin and then roll a six-sided die. How many possible combinations are there?
13. Christmas Day In leap years was 53 Sundays. On what day of the week fell to Christmas Day?
14. Slope of the pool Calculate slope (rise:run) of the bottom of swimming pool long 30 m. Water depth at beginning of pool is 1.13 m (for children) and depth at end is 1.84 m (for swimmers). Slope express as percentage and as angle in degrees.
15. Leveling Calculate how many 25 kg bags of leveling concrete must be purchased if we leveling room 15 m2 to the "height" 6 mm if consumtion is 1.5 kg per square meter and millimeter thickness.
16. Drunk man Drunkman has 2.6‰ of alcohol in the blood. How many grams of alcohol has in blood, if he have 5 kg of blood?
17. Wheat The rectangle shaped field with dimensions 889 m and 1336 m harvested last year was 6235 q wheat. (1 q = 1 quintal = 100 kg). During the year, it was necessary to fix the pipe and therefore did kick wide 3 m parallel to the side of the field 1336 m, where.
18. Hexagonal prism The base of the prism is a regular hexagon consisting of six triangles with side a = 12 cm and height va = 10.4 cm. The prism height is 5 cm. Calculate the volume and surface of the prism!
19. Divisibility Determine the smallest integer which divided 11 gives remainder 4 when divided 15 gives remainder 10 and when divided by 19 gives remainder 16.
20. Shooter The shooter fired to a target from distance 11 m The individual concentric circle of targets have a radius increments 1 cm (25 points) by 1 point. Shot was shifted by 8'(angle degree minutes). How many points should win his shot?

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