# Examples for 9th grade - page 5

- Katy MO

Kate draw triangle ABC. Middle of AB have mark as X and the center of the side AC as Y. On the side BC wants to find the point Z such that the content area of a 4gon AXZY was greatest. What part of the triangle ABC can maximally occupy 4-gon AXZY? - River

Calculate how many promiles river Hudson average falls, if on section long 921 km flowing water from 1224 m AMSL to 154 m AMSL. - Two workers

Two workers together execute some work in 10 days. The first worker would have done himself in 20 days. How many days would have done himself a second worker? - Accidents

The count of accidents in 1993 caused 8009 women which is 7.1%. How many men caused the accidents? - Area of RT

Calculate the area of a right triangle which hypotenuse has length 20 and one hypotenuse segment has lenght 15. - Z9–I–1

In all nine fields of given shape to be filled natural numbers so that: • each of the numbers 2, 4, 6 and 8 is used at least once, • four of the inner square boxes containing the products of the numbers of adjacent cells of the outer square, • in the cir - Lathe

From the cube of edge 52 cm was lathed maximum cylinder. What percentage of the cube is left as waste after lathed? - Chords

How many 6-tones chords (chord = at the same time sounding different tones) is possible to play within 10 tones? - Cubes

Cube, which consists of 27 small cubes with edge 3 dm has volume: - Sale

If the product twice price cut by 20%, what percentage was price cut in total? - Ravens

The tale of the Seven Ravens were seven brothers, each of whom was born exactly 1.5 years after the previous one. When the eldest of the brothers was 4-times older than the youngest, mother all curse. How old was seven ravens brothers when their mother cur - Wiring

Conduit has a cross section 22^{2}mm. Maybe put it into 6 conductors with a cross section S2 $mm^{2}? - Commitee

A class consists of 5 males and 18 females. How many committees of 4 are possible if the committee must consist of 3 males and 1 females? - Tetrahedral pyramid

What is the surface of a regular tetrahedral (four-sided) pyramid if the base edge a=23 and height v=8? - Kites

Boys run kite on a cable of 86 meters long. What is the kite altitude, if the angle from the horizontal plane is 77°? - Acreage

What acreage has a rectangular plot whose diagonal is 34 meters long and one side has a length of 16 meters. ? - Pentagon

Within a regular pentagon ABCDE point P is such that the triangle is equilateral ABP. How big is the angle BCP? Make a sketch. - Clock

How many times a day hands on a clock overlap? - Phone numbers

How many 9-digit telephone numbers can be compiled from the digits 0,1,2,..,8,9 that no digit is repeated? - Friends in cinema

5 friends went to the cinema. How many possible ways can sit in a row, if one of them wants to sit in the middle and the remaining's place does not matter?

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