# Examples for 9th grade - page 4

- Painter Pavel

Painter Pavel painted the fence for 20 hours and painter Petr the same fence painted for 17 h. How long should take painted the fence together? - Amazing number

An amazing number is name for such even number, the decomposition product of prime numbers has exactly three not necessarily different factors and the sum of all its divisors is equal to twice that number. Find all amazing numbers. - Right Δ

Right triangle has length of one leg 7 cm and length of the hypotenuse 25 cm. Calculate the height of the triangle. - KLMN

In the trapezoid KLMN is given this informations: 1. segments KL and MN are parallel 2. segments KL and KM has same length 3. segments KN, NM and ML has same length. Determine the size of the angle KMN. - Cylinder - h

Cylinder volume is 129 cm^{3.}Base radius is 3 cm. Calculate the height of the cylinder. - Elections

In elections candidate 8 political parties. Calculate how many possible ways can the elections finish, if any two parties will not get the same number of votes. - Beer

After three 10° beers consumed in a short time there are 7.4 g of alcohol in 5 kg adult human blood. How much is it per mille? - AVG of INT

What is the average of the integers from 7 throuht 15 inclusive? - 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 - Trigonometry

Is true equality? ? - Coin and die

Flip a coin and then roll a six-sided die. How many possible combinations are there? - Diofant 2

Is equation ? solvable on the set of integers Z? - MO SK/CZ Z9–I–3

John had the ball that rolled into the pool and it swam in the water. Its highest point was 2 cm above the surface. Diameter of circle that marked the water level on the surface of the ball was 8 cm. Determine the diameter of John ball. - Line

Line p passing through A[-10, 1] and has direction vector v=(2, 4). Is point B[-20, -19] on the line p? - Diagonal

Calculate the length of the diagonal of the rectangle ABCD with sides a = 7 cm, b = 6 cm. - Mr Novak

Mr Novak earns an average 638 euros. When increasing the salary they gave him a choice: ? What is better choice for Mr Novak? - Saving

Kevin save € 4620 to buy a car. Yet it lacks save 65% of the car price. How much is the car? - Drunk man

Drunkman has 2.1‰ of alcohol in the blood. How many grams of alcohol has in blood, if he have 6 kg of blood? - Tractors

Fields go plow two tractors with various performance. The first tractor plow whole field in 5 hours, the second tractor plow whole field 5 hours longer. How long take plow whole field with two tractors? - Examination

The class is 22 students. How many ways can choose four to examination?

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