Examples for 8th grade - page 48
Surface of the sphere is 2260 cm2, weight is 52.2 kg. What is its density?
VAT is a tax which the state artificially betrays goods and services for final consumption. VAT in Slovakia is 20%. Calculate how much percent pay less tax residents of Switzerland, when VAT is only 8%.
- Triangle SAS
Calculate area and perimeter of the triangle, if the two sides are 19 cm and 80 cm long and angle them clamped is 90°.
The rectangular crossroads comes passenger car and an ambulance, the ambulance left. Passenger car is at 45 km/h and ambulance 58 km/h. Calculate such a relative speed of the ambulance moves to the car.
The baker makes from 10 kg of flour 12 kg dough. How much flour he need to make a 100 kg dough?
- Sides od triangle
Sides of the triangle ABC has length 4 cm, 5 cm and 7 cm. Construct triangle A'B'C' that are similar to triangle ABC which has a circumference of 12 cm.
9 workers dig a canal 120 meters long for eight hours. For how long would be dig five workers canal 200 meters long?
Miko and Anton have a total of 1,580 blueberries. Miko and Anton have them in the ratio 2: 3. Determine how much each of them has.
- UN 1
If we add to an unknown number his quarter, we get 210. Identify unknown number.
A pit is dug in the shape of a cuboid with dimensions 10mX8mX3m. The earth taken out is spread evenly on a rectangular plot of land with dimensions 40m X 30m. What is the increase in the level of the plot ?
- Train expres
At 8.00 strarted from Bratislava to Poprad express Tatry. Cities are distant 340 kilometers. At the same time started from Poprad express Danube to Bratislava. Express Tatry's average speed is 80 km/h, Danube 90 km/h. At what distance from Poprad trains w
From the money that was in my Maria wallet she spent a fifth on the first purchase. From remain money she could buy 2 kg of strawberries. But she bought only 1.5 kg for 60 Kc. How much money was Marie originally in her wallet?
One-fifth of the monthly pocket money contributes Maros for food for his cat, half of the rest postpone for a new smartphone. The remaining € 8 spend. How much pocket money gets Maros a month?
- Reduce of the volume
Calculate how many % reduce the volume of the cube is we reduced length of each edge by 10%.
- Cube 9
What was the original edge length of the cube if after cutting 39 small cubes with an edge length 2 dm left 200 dm3?
Calculate the percentage of waste if the cube with 52 cm long edge is lathed to cylinder with a maximum volume.
- Tank 9
The tank with volume V is filled with one pump for three hours and by second pump for 5 hours. When both pumps will run simultaneously calculate: a) how much of the total volume of the tank is filled in one hour b) for how long is the tank full
- Cube from sphere
What largest surface area (in cm2) can have a cube that was cut out of a sphere with radius 22 cm?
In the garden with an area of 8 ares rain 40hl of water. To what heights leveled water?
How many euros we will pay for repainting the room shaped cuboid with a length of 4.5 meters, width of 2.5 meters and a height of 3 meters, if for 1 m2 with paint we pay € 1.5?