Examples for 9th grade - page 41
- Machines 2
2 machines for 50 hours produces 2,000 products. How many machines need to buy to make in 30 hours 15,000 products?
- Rectangle Anton
Difference between length and width of the rectangle is 18. Length is 2-times larger than the width. Calculate the dimensions of the rectangle.
The rectangle is 18 cm long and 10 cm wide. Determine the diameter of the circle circumscribed to rectangle.
Rectangular hall will have pave by square tiles with a side length 15 cm. The hall has length 18 meters and width 3 m. How many tiles need to buy if 2 percent of the amount is disrupted during the work?
- Water level
The glass container has a cuboid shape with dimensions of the bottom 24 cm and 12 cm. The height of water is 36 cm. Calculate the volume of the body, which are sunk into the water if the water level rise by 3 cm.
- Rectangular trapezoid
Calculate the content of a rectangular trapezoid with a right angle at the point A and if |AC| = 4 cm, |BC| = 3 cm and the diagonal AC is perpendicular to the side BC.
Loggers wanted to seed more than 700 and less than 800 trees. If they seed in rows of 37, left them 8 trees. If they seed in rows of 43, left the 11 trees. How many trees must seed ?
The car accelerates at rate 0.5m/s2. How long travels 400 meters and what will be its speed?
- Circular flowerbed
Circular flowerbed with diameter 8 m we split by concentric circle to circle and annulus with the same area. Determine the radius of the circle.
Both dimensions of the rectangular parcel were increased by 40%. By how many % has increased its acreage?
- Barrel 2
Empty barrel weighs 12 kg. When it filled with water up to 46% height, weighs 68 kg. How heavy is barrel full of water?
Outer perimeter of silo is 24 m. Concrete wall is 18 cm thick. What is diameter and area of inside floor of silo?
To a semicircle with diameter 10 cm inscribe square. What is the length of square sides?
- Total displacement
Calculate total displacement of the 12-cylinder engine with the diameter of the piston bore B = 6.8 cm and stroke S=2 cm of the piston. Help: the crankshaft makes one revolution while the piston moves from the top of the cylinder to the bottom and back t
In how many ways can be placed 6 athletes on the podium at the Olympics? Depend on the color of the metal.
- Midpoint of segment
Point A has coordinates [15; 1] and the midpoint of the segment AB is the point [-20; 13]. What are the coordinates of point B?
- Miraculous tree
Miraculous tree grows so fast that the first day increases its height by half the total height of the second day by the third, the third day by a quarter, etc. How many times will increase its height after 8 days?
- Cube corners
From cube of edge 8 cm cut off all vertices so that each cutting plane intersects the edges 2 cm from the nearest vertice. How many edges will have this body?
Some friends had to collect the sum 72 EUR equally. If the three refused their part, others would have to give each 4 euros more. How many are friends?
- Tractor wheels
Smaller tractor wheel has a circumference of 3 meters, bigger 4 meters. On what path executes smaller wheel 6 turns over more bigger?