Examples for 9th grade - page 18
Mr. Gherkin use for fertilization 9% solution of fertilizer. 7 liters of it still left. How much water must be added to the solution to make only 5% solution?
- Circle in rhombus
In the rhombus is inscribed circle. Contact points of touch divide the sides to parts of length 18 cm and 17 cm. Calculate the circle area.
- Height difference
What height difference overcome if we pass road 1 km long with a pitch21 per mille?
- 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%.
- Water inlets
Inlet valve with a flow rate of 12 liters per second is filled tank for 72 minutes. How long take to fill full tank if we open one more such valve half an hour after?
- Water tank
Water tank shape cuboid has a width of 3.3 m and length twice larger. How high will reach water if water flow into 15 liters of water per second during 23 minutes?
We will throw two dice. What is the probability that the ratio between numbers on first and second dice will be 1:2?
The rod are 1.7 m long hanging weights 2 kg and 12 kg on ends. Where are centre of rod (distance from weight 2 kg) to be in balance?
- Lord Ram
When lord Ram founded the breed white sheep was 8 more than black. Currently white sheep are four times higher than at the beginning and black three times more than at the beginning. White sheep is now 42 more than the black. How many white and black sh
In the middle of a cylindrical tank with a bottom diameter 350 cm is standing rod which is 31 cm above the water surface. If we bank rod its end reach surface of the water just by the tank wall. How deep is the tank?
Workers digging a jump pit in the school yard. Pit has a cuboid shape with a length 20 m, a width 20 dm and depth 36 cm. They excavate 0.4 cubic meters of soil an hour. How much time (hours and minutes) is need to the excavate this pit?
- Triangular prism
The base perpendicular triangular prism is a right triangle whose hypotenuse measures 13 cm and one cathetus 2 cm. Height of the prism is equal to 10/7 of the perimeter of the base. Calculate the surface area of prism.
Cinema auditorium is built for 1740 people. The first row is planned for 29 seats and each next gradually 2 more. How many rows of seats will have auditorium?
- Two workers
The first worker completed the task by himself in 9 hours, the second in 18 hours. After two hours of joint work left first worker to a doctor and the second finished the job himself. How many hours worked second worker himself?
- Event probability
The probability of event G in 9 independent experiments is 0.48. What is the probability that the event G occurs in one experiment (probability is same)?
Use law of square roots roots: ?
- Inscribed rectangle
The circle area is 184. Determine the area of inscribed rectangle with one side 10 long.
Price of the new machine is € 56000. Every year is depreciated 16% of residual value. What will be the value of the machine after 5 years?
- Hexagonal prism
The base of the prism is a regular hexagon consisting of six triangles with side a = 12 cm and height va = 10.4 cm. The prism height is 5 cm. Calculate the volume and surface of the prism!
- Sales vs profit
Apple sells 45 percent less computes than the Acer but the profit from their sales is 1.7 times higher than Acer. How many times are Apple computer more expensive than Acer?