Examples for 8th grade - page 49
- Flowerbed 2
Around the square flower bed in a park is sidewalk 1.4 m wide. The area of this sidewalk is 125 m2. What is the area of the flowerbed?
In the three-part tram went 109 passengers in front of others, 92 after others and in the middle half of all. How many passengers went in tram total?
- Ice cream in cone
In the ice cream cone with a diameter of 3.6 cm is 0.9 dl of ice cream. Calculate the depth of the cone.
- RT 10
Area of right triangle is 17 cm2 and one of its cathethus is a=8 cm. Calculate perimeter of the triangle ABC.
What must be the elevation of an observer in order that he may be able to see an object on the earth 814 km away? Assume the earth to be a smooth sphere with radius 6378.1 km.
- XY triangle
Determine area of triangle given by line -7x+7y+63=0 and coordinate axes x and y.
What is the slope of the perpendicular bisector of line segment AB if A[-9,-8] and B[-8,0]?
What angle rising stairway if step height in 17 cm and width 24 cm?
How much of a mixed forest rangers want to cut down, if their head said: "We only cut down pine trees, which in our mixed forest 96%. After cut pine trees constitute 91% of all trees left."
Suppose that tourist went on foot over the Globe equator. How many meters more track made his hat on his head as the shoes on your feet? The radius of the earth is 6378 km and height of the tourist is 1.7 m.
- Square vs rectangle
Square and rectangle have the same area contents. The length of the rectangle is 9 greater and width 6 less than side of the square. Calculate the side of a square.
- Rectangle diagonals
It is given rectangle with area 24 cm2 a circumference 20 cm. The length of one side is 2 cm larger than length of second side. Calculate the length of the diagonal. Length and width are yet expressed in natural numbers.
Meadow with an area of 1,500 square meters was fertilized with 12 kg of urea. Urea contains 45% nitrogen. How much nitrogen accounted per 1 m2?
- Linear system
Solve this linear system (two linear equations with two unknowns): x+y =36 19x+22y=720
- Spain vs USA
Spain lost to the US by 4 goals. In the match total fell 10 goals. How many goals gave the Spain and how the United States?
Bookshelve with an original price of € 200 twice become cheaper. After the second discounted by 15% the price was € 149.60. Determine how much % become cheaper for the first time.
- PC disks
Peter has 45 disks in three colors. One-fifth of the disks are blue, red are twice more than the white. How much is blue, red and white disks?
- UN 1
If we add to an unknown number his quarter, we get 210. Identify unknown number.
- Ice cream
Annie likes much ice cream. In the shop are six kinds of ice cream. In how many ways she can buy ice cream to three scoop if each have a different flavor mound and the order of scoops doesn't matter?
- Rectangle from string
String 12m. Make rectangle when one side is two times longer than its width.