Examples for 9th grade - page 7
- 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?
- Octahedron - sum
On each wall of a regular octahedron is written one of the numbers 1, 2, 3, 4, 5, 6, 7 and 8, wherein on different sides are different numbers. For each wall John make the sum of the numbers written of three adjacent walls. Thus got eight sums, which also.
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
Cube, which consists of 27 small cubes with edge 3 dm has volume:
If the product twice price cut by 20%, what percentage was price cut in total?
Determine the radius of the circumscribed circle to the right triangle with legs 3 cm and 3 cm.
From the cube of edge 52 cm was lathed maximum cylinder. What percentage of the cube is left as waste after lathed?
Conduit has a cross section 492 mm. Maybe put it into 5 conductors with a cross section S2 $mm2?
How many 6-tones chords (chord = at the same time sounding different tones) is possible to play within 10 tones?
- Phone numbers
How many 9-digit telephone numbers can be compiled from the digits 0,1,2,..,8,9 that no digit is repeated?
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?
- Climb in percentage
The height difference between points A and B is 442 m. Calculate the percentage of route climbing if the horizontal distance places A, B is 6.8 km.
- Tetrahedral pyramid
What is the surface of a regular tetrahedral (four-sided) pyramid if the base edge a=23 and height v=8?
How many times a day hands on a clock overlap?
- 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?
- Two tributaries
Two tributaries of the pool fill it in 10 hours. One of the tributaries would fill 15 hours. How long would fill the first tributary?
Five painters painting the fence for eight days. How many days over will take work if paint the fence only four decorators?
Semicircle estate must be fence. The straight section has 44 meters long fence. How many meters of fence should buy?
- Square grid
Square grid consists of a square with sides of length 1 cm. Draw in it at least three different patterns such that each had a content of 6 cm2 and circumference 12 cm and that their sides is in square grid.
- Lie/do not lie
The function is given by the rule f(x) = -x-12. Determine whether point D[-4; 2] lies on this function. Solve graphically or numerically and give reasons for the your answer.