Examples for 9th grade - page 6
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?
How many times a day hands on a clock overlap?
Boys run kite on a cable of 86 meters long. What is the kite altitude, if the angle from the horizontal plane is 77°?
- 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?
Determine the radius of the circumscribed circle to the right triangle with legs 3 cm and 10 cm.
Within a regular pentagon ABCDE point P is such that the triangle is equilateral ABP. How big is the angle BCP? Make a sketch.
- 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.
- Trapezoid MO-5-Z8
ABCD is a trapezoid that lime segment CE divided into a triangle and parallelogram as shown. Point F is the midpoint of CE, DF line passes through the center of the segment BE and the area of the triangle CDE is 3 cm2. Determine the area of the trapezoid A
Semicircle estate must be fence. The straight section has 44 meters long fence. How many meters of fence should buy?
Three siblings Helena, Oliver and George split the bag with candies on merit in the ratio 1:6:3. How many candies should each get if in bag were 210?
- Shadow and light
Nine meters height poplar tree has a shadow 16.2 meters long. How long shadow have at the same time Joe if he is 1,4m tall?
- 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.
Cinema auditorium is built for 3591 people. The first row is planned for 39 seats and each next gradually 3 more. How many rows of seats will have auditorium?
It is true that the lines that do not intersect are parallel?
- Sphere growth
How many times grow volume of sphere if radius rises 3×?
Cylinder shell has the same content as one of its base. Cylinder height is 25 m. What is the radius of the base of the cylinder?
On the meadow grazing horses, cows and sheep, together less than 200. If cows were 45 times more, horses 60 times more and sheep 35 times more than there are now, their numbers would equall. How many horses, cows and sheep are on the meadow together?
- Daily average
Calculate the average temperature during the day, when 14 hours was 20 °C and 10 hours was 15 °C.