Examples for 8th grade - page 62
If the segment of the line y = -8x +4 that lies in quadrant I is rotated about the y-axis, a cone is formed. What is the volume of the cone?
Area of the side of two cylinders is same rectangle of 45 cm × 32 cm. Which cylinder has a larger volume and by how much?
- Trains for people
It is said that the train is synonymous to delay. Calculate the average speed of travel by train long 50 km, with regular train leave at 6:05 and arrive at 7:20, but train is late and has departure at 9:52 and arrive at 11:05.
One cube is inscribed sphere and the other one described. Calculate difference of volumes of cubes, if the difference of surfaces in 137 cm2.
Calculate radius of the Circumscribed circle in the rectangle with sides 17 and 16. It can be rectangle inscribed by circle?
- Carbon dioxide
Calculate how many grams of oxygen are in 126 g of carbon dioxide CO2. Relative atomic mass of oxygen is 16 and of carbon is 12.
- Extreme temperatures
USA hit extreme heat wave. Calculate percentage of the air temperature change from normal summer temperature 24 °C to 37 °C.
- Widescreen monitor
Computer business hit by a wave of widescreen monitors and televisions. Calculate the area of the LCD monitor with a diagonal size 17 inches at ratio 4:3 and then 16:9 aspect ratio. Is buying widescreen monitors with same diagonal more advantageous tha
- Glass mosaic
How many dm2 glass is nessesary to produc 50 slides of a regular 6-gon, whose side has length 7 cm? Assume that cutting glass waste is 14%.
- Cone in cube
The cube is inscribed cone. Determine the ratio of the volume of cone and cube. The ratio express as a decimal number and as percentage.
Rhombus-shaped jewel have area of 86 mm2 and the edge in long 10 mm. Calculate the size of rhombus acute angle.
- Triangle SAA
The triangle has one side long 34 m and its two internal angles is 60°. Calculate the perimeter and area of the triangle.
Bomber flies 5 km at 1400 km/h. At what horizontal distance from the target, must pilot drop the bomb to hit the target? Don't care about air resistance and consider the gravitational acceleration g=9.81 m/s2.
- Temperature calculus
Calculate percentage of temperature increase if changed from -6 °C to 2 °C?
- Required reserves
Calculate what is the minimum amount of money that bank must hold in cash from your deposit 2100 Eur. How much money is ideally created in the banking system from your deposit if the level of minimum reserve requirement is 2.01%? Consider fractional re
- Ice and water
We want to cover rectangular rink with dimensions of 55 m and 25 m with 4cm thick layer of ice. How many liters of water we need if after freezing water increases its volume by 10%?
Daniela and Michael would jointly dug potatoes for 7.5 hours. But if Daniela was working alone she would take 2.5 hours more as if he were working with Michael. Determine how much for the work done by Michael himself and how much Daniela herself.
Solve algebrogram: mama+anna=vari How many solutions are?
- Pet store
In a pet store, they are selling out the fish from one aquarium. Ondra wanted half of all fish, but they don't wish cut by hal fany fish he got one more than demanded. Matthew wished the remaining half of the fish, but as Andrew got half the fish more th
- Money duo
Julius and Mark have together 45 euros. Mark has 50% more money than Julius. Determine the amount of money that have Mark and Julius.