Math practice for 13 year olds - page 425 of 434
Number of problems found: 8668
- Gear
Two gears fit into each other and have a transfer of 1:2. The centers of gears are spaced 96 cm. What are the radii of the gears?
- Tinsmith
Tinsmith constructs chimney pipe 186 cm long and 16 cm wide. A pipe is made from the plate overlap at the joint and needs to add $x cm width of the plate. What dimensions of the sheet will have to be prepared for the construction?
- Cubes
Surfaces of cubes, one of which has an edge of 48 cm shorter than the other, differ by 36288 dm². Determine the length of the edges of these cubes.
- Free fall
Pavel fall from height 9 m. Calculate the speed at which he hit the ground when falling with acceleration g = 9.81 m/s²
- Subway
The Subway train went between two stations that gradually accelerated for 26 seconds and reached a speed of 72 km/h. At this rate, it went 56 seconds. Then 16 seconds slowed to a stop. What was the distance between the stations?
- Cuboid
Find the dimensions of cuboids a, b, and c; if diagonal d=9 dm has an angle with edge α=55° and has an angle with edge b β=58°
- Rail turn
The curve radius on the railway line is 532 m. The length of the rail track on it is 818 m. How many degrees is the angle ASB if A and B are boundary points and S is the center of the arc curve?
- Cone
The circular cone has height h = 15 dm and base radius r = 2 dm slice plane parallel to the base. Calculate the distance of the cone vertex from this plane if solids have the same volume.
- ŽSR
Calculate fixed annual personnel costs of operating monorail line 143 km long if every 5 km is a station that serves three people - one dispatcher and two switchmen in 4-shift operation. Consider the average salary of the employee 884 euro.
- Salary
Calculate the equivalent annual salary to an hourly wage of $ 15. Assume a 33-hour workweek.
- The www server
Calculate how many average minutes the web server is unavailable a year if the availability is 99.9999%.
- Pool
If water flows into the pool through two inlets, it will fill for 5 hours. If the first inlet fills the pool 5 hour longer than the second, how long does it take to fill with two inlets separately?
- Coin
How many 5-cent coins must be put in a row so that the next 5-cent coins after them (above) are rolled on its axis?
- Triangle
Calculate the area of the right triangle ΔABC if one leg is long 12 and its opposite angle is 47°.
- Wiring
The conduit has a cross-section 54² mm. Maybe put it into 6 conductors with a cross section S2 $mm²?
- Wheat
The rectangle-shaped field with dimensions 1268 m and 745 m harvested last year was 4959 q wheat. (1 q = 1 quintal = 100 kg). During the year, it was necessary to fix the pipe and therefore did kick wide 4 m parallel to the side of the field 745 m, were n
- Blood
In the human body, the blood is about 7.3% body weight. How many kilograms of blood are in the human body with a weight of 91 kg?
- River
Calculate how many permille river Hudson average falls, if on section long 952 km flowing water from 1231 m AMSL to 131 m AMSL.
- Cube
The cube weighs 11 kg. How weigh is a cube of the same material if its dimensions are 3-times smaller?
- Fraction
For what x expression (4x²-16)/(3x² -6x) equals zero?
Do you have unsolved problem that you need help? Ask a question, and we will try to solve it. Solving math problems.