Examples for 8th grade - page 50
The volume of tetrahedral prism is 2.43 m3. Base of prism is a parallelogram in which a side 2,5dm and height ha = 18cm. Calculate the height of the prism.
What distance will describe the tip of minute hand 6 cm long for 20 minutes when we know the starting position with finally enclose hands each other 120°?
- Jane and Miro
Jane brother Miro is 42 years. And he is three times old as it was Jane when Miro was for so many years as there are now Jane. How old is Jane?
- Two cars
From the town A to town B started two cars. The first at 7:00 at average speed 60 km per hour, the second at 10:00 at average speed 100 km per hour. The first car will not stay in B, and on the way back meet the second car at half way from A to B. At what.
How long distance will travel a large (minute) hand on the clock for 39 minutes, if its length is 33 cm?
I have bevel in the ratio 1:6. What is the angle and how do I calculate it?
Mother bought 5 boxes of milk and 7 kg of potatoes and paid a total CZK 147. Aunt bought 7 boxes of milk and 3 kg of potatoes and paid 131 CZK. What is the price of one carton of milk and 1 kg of potatoes? How CZK together would have saved if bought at the
Half a kilogram of pork and three-quarters of a kilogram of beef cost total 6.6 USD. One quarter of a kilogram of beef and 1 kilogram of pork cost 6.3 USD. Determine the price of 1 kg of each type of meat.
- Hexagon 5
The distance of parallel sides of regular hexagonal is 81 cm. Calculate the length of the radius of the circle described to this hexagon.
Solve the inequation: 5k - (7k - 1)≤ 2/5 . (5-k)-2
- EQL triangle
Calculate inradius and circumradius of equilateral triangle with side a=100 cm.
Flowerbed has the shape of an isosceles obtuse triangle. Arm has a size 6.1 meters and an angle opposite to the base size is 93°. What is the distance from the base to opposite vertex?
The perimeter of a circular sector with an angle 2 rad is 53 cm. Determine the radius of the circle from which the sector comes.
The shooter fired to a target from distance 9 m The individual concentric circle of targets have a radius increments 1 cm (25 points) by 1 point. Shot was shifted by 16'(angle degree minutes). How many points should win his shot?
- Against each other
From two points A, B distant 45 km at the same time started two cars against each other at speeds 81 km/h and 67 km/h. How long does cars meet and what distance passes each of them?
- Map - climb
On the map of High Tatras in scale 1:25000 are cable car stations in the Tatranska Lomnica and in the Skalnate Pleso with distance 156 mm. Altitude of this stations are 944 m and 1755 m. What is average angle of climb of this cable car track?
What is the weight of concrete cover (lid) to round shape well with a diameter 1.3 m, if the thickness of the cover is 15 cm? 1 m3 of concrete weighs 2190 kg.
What is the slope of the perpendicular bisector of line segment AB if A[-9,-8] and B[-8,0]?
- Wire D
Wire length 5 m is bent so that it forms a semicircle circuit (including the diameter). Determine the radius of the semicircle.
- Right isosceles
Calculate area of the isosceles right triangle which perimeter is 35 cm.