Examples for 8th grade - page 66
- Concrete pipe
How much will cost cover a 6 m long concrete pipe with an outer radius 1.5 m and inner radius 0.8 meters if 1 m2 paint costs 24 €.
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 ?
- Tripled square
If you tripled the length of the sides of the square ABCD you increases its content by 200 cm2. How long is the side of the square ABCD?
- Pages of book
Lenka calculated that if every day to read 16 pages of the book, read a book a day earlier than had read only 14 pages a day. How many pages has this book?
- Chors centers
The circle with a diameter 17 cm, upper chord /CD/ = 10.2 cm and bottom chord /EF/ = 7.5 cm. The midpoints of the chords H, G is that /EH/ = 1/2 /EF/ and /CG/ = 1/2 /CD/. Determine the distance between the G and H, if CD II EF (parallel).
- Three friends
Divide 570 euros to three friends so that first will get 50 euros less than the second and third twice more than the first. How many euros will get everyone?
- Concrete block
Determine the volume of concrete block whose one edge of the base has a length 3 meters, body diagonal is 13 meters and its height is 12 meters.
Perimeter of rectangle is 48 cm. Calculate its dimensions if they are in the ratio 5:3 (width:height)
- Little hand
What angle shifted little hand on the clock after one hour and 38 minutes?
- Octagonal mat
Octagonal mat formed from a square plate with a side of 40 cm so that every corner cut the isosceles triangle with leg 3.6 cm. What is the content area of one mat?
- Bus and Milan
The bus started from the village at speed 60 km/h. After one kilometer, when Milan came to bus stop on a motorcycle with grandmother. When they found that bus drove away he try to catch it. At the next stop, a distance of 3km caught up bus. How quickly had
- Force meter
We put the statuette on the force meter. The force meter showed a value 25 N. Then we placed the statuette on the force meter completely immersed in the water. The force meter showed a value 17 N. What is the volume of the statuette?
- Car and cyclist
Cyclist started from town at speed 18 km/h. After 1 hour 30 min started the car from town and caught up with the cyclist in 50 minutes. How fast was a car?
Find the volume and surface area of prism with base of an equilateral triangle with side 7 dm long and the body height of 1.5 m.
- Fe vs. H2O
The volume of what the body of the same weight is greater - iron or water?
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?
- Fewer than 500 sheep,
There are fewer than 500 sheep, but if they stand in a double, triple, quadruple, five and sixth order, one sheep will remain. But they can stand in the seventh order. How many are sheep?
- Hexadecimal number
What will be hexadecimal number 240 as decimal number?
If Alena give Lenka 3 candy will still have 1 more candy. If Lenka give Alena 1 candy Alena will hame twice more than Lenka. How many candies have each of them?
Divide the string length 800 cm in ratio 1: 5