Examples for 9th grade - page 27
- Angles ratio
In a triangle ABC true relationship c is less than b and b is less than a. Internal angles of the triangle are in the ratio 5:4:9. The size of the internal angle beta is:
- Sun rays
If the sun's rays are at an angle 60° then famous Great Pyramid of Egypt (which is now high 137.3 meters) has 79.3 m long shadow. Calculate current height of neighboring chefren pyramid whose shadow is measured at the same time 78.8 m and the current hei
The first tributary fill pool with water in 15 hours. The second tributary fill pool in 10 hours. For how many hours the pool is filled with both tributaries?
Calculate height and volume of a regular tetrahedron whose edge has a length 11 cm.
Help little C.F. Gauss sum all the integers from 1 to 340.
Bomber flies 5 km at 1400 km/h. At what horizontal distance from the target, must pilot drop the bomb to hit the target? Don't care about air resistance and consider the gravitational acceleration g=9.81 m/s2.
- Tourist Jirka
Distance between the points A and B is 13.5 km. Jirka went from point A to point B unknown speed and for an unknown period of time. Back to the point A went slower by 3 km/h which means that went 20 minutes more. How long Jirka took the return journey?
- Cube - wall
V kocke ABCDEFGH je ?. Aký je povrch kocky?
- Quadratic equation
Solve quadratic equation: x2+16x-225=0
The driver of a car is to get to 378 km distant city. From atlas found that 99 km will have to pass through the cities at average speed 48 km/h. Remainder of the journey pass outside the cities at average speed 117 km/h. Calculate how many hours it will ta
- Two diggers
There are two diggers. One digger digs a pit 83 hours second gidding 1.4 times faster. a) how long took to dig a pit second digger b) how long took dig together
- Diamond ABCD
In the diamond ABCD is the diagonal e = 24 cm and size of angle SAB is 28 degrees, where S is the intersection of the diagonals. Calculate the circumference of the diamond.
- Iron fence
One field of iron fence consists of 20 iron rods with square cross-section of 1.5 cm side and a long 1 meter. How much weight a field if the density of iron is 7800 kg/m3.
- Racing track
On the racing track circling three cars. The first passes one circuit for 8 seconds, the second for 16 seconds and a third for 15 seconds. a) Calculate number of seconds since the start to catch all three cars together for the first time again across the.
- Sphere cuts
At what distance from the center intersects sphere with radius R = 60 plane, if the cut area and area of the main sphere circle is in ratio 3/6.
- Two cars
From the town A to town B started two cars. The first at 7:00 at average speed 60 km per hour, the second at 10:00 at average speed 100 km per hour. The first car will not stay in B, and on the way back meet the second car at half way from A to B. At what.
- Volume and surface
Calculate the volume and surface area of the cylinder when the cylinder height and base diameter is in a ratio of 3:4 and the area of the cylinder jacket is 24 dm2.
The first racer run at a speed 12 m/s and is 470 meters before the finish and ahead 22 meters before second competitor. At what speed must run the second racer to catch first racer at the finish line?
- Grandson and granddad
Grandson with grandpa they counted how many years have together. Their product is 365. How many years is the sum of their years.
- Ice cream in cone
In the ice cream cone with a diameter of 3.6 cm is 0.9 dl of ice cream. Calculate the depth of the cone.