Math practice for 13 year olds - page 85 of 429
Number of problems found: 8562
- Apprentice cost reduction
The apprentice came to his master with an improvement proposal, and with better work organization, we will reduce costs by 45% this year, 30% next year, and 25% the following year. The production won't cost us anything. Has the apprentice received a rewar - Triangle perimeter similarity
Calculate the perimeter of triangle ABC if you know that it is similar to triangle EFG in which e=144 mm, f=164 mm, g=92 mm, and the similarity ratio is 4. Express the result in cm. - Maple model shadow
In the camp, the children made a mock-up of the campsite. In its center was a maple, which had a height of 28 cm on the model. Calculate the height of the maple in the campsite if, in the morning, it casts a shadow 14 m long and its model has a shadow 49 - Cylinder volume calculation
How tall is a cylinder whose shell has a volume equal to the base? What is the volume of this cylinder? - Quadrilateral perimeter angles
Quadrilateral ABCD has side lengths AB=13cm, CD=3cm, AD=4cm. Angles ACB and ADC are right angles. Calculate the perimeter of quadrilateral ABCD. - Trapezoid cross section
Calculate how many hectoliters of water can fit in a fifty-meter sloped pool; if the smallest depth is 1.2 m and the largest depth is 3 m, the width of the pool is 20 m. - Percentage thirty-seven forty-nine
Calculate what percentage is €37 from €49. - Aquarium volume half
Pavel has a cube-shaped aquarium with a volume of 240 liters. Thomas has an aquarium whose all dimensions are half the dimensions of Paul's aquarium. What is the volume of Thomas's aquarium? - Bear weight percentage
The bear weighed 410 kg at the beginning of winter and lost 10 percent during hibernation. He gained 10 percent of his weight from spring to fall. Find out if the bear's weight was greater at the beginning of winter or autumn by what percentage. - Cooker efficiency testing
When testing the effectiveness of an electric cooker with data of 220 V, 1200 W, 1 kg of water at a temperature of 15 degrees Celsius was boiled for 8.5 minutes. Calculate the stove efficiency corresponding to these data - Percentage twelve sixty Calculate what percentage is 12€ of 60€.
- Current wire resistance
The current I = 4A branches into three wires with resistances R1 = 2Ώ, R2 = 5Ώ, R3 = 10Ώ. Calculate the total resistance of the connection and the voltage of the source. How big are the currents in each wire? - Current in the bulb
The bulb is rated 6 V, 0.2 A. Determine the current rating of the bulb. - Circuit breaker power
The electric circuit breaker automatically switches off the circuit of the 220 V electrical network at a current of 6 A. Determine the maximum power in the protected circuit. - Cooker heat generation An immersion cooker has a resistance of 30 ohms and is connected to a voltage of 120 V. How much heat is generated in 2 hours?
- Bulb consumption hours A current of 500 mA passed through the filament of a light bulb with a resistance of 400 ohms. What is the consumption of a light bulb in 5 hours?
- Cooker plate resistance The immersion cooker plate has data 220 V, 300 W. What is the resistance of the heating wire?
- Iron plate resistance The electric iron plate has written 220 V, 1200 W. What is the resistance of the heating wire?
- Triangle middle crossbar
Calculate the length of the middle crossbars in an isosceles triangle if the length of the arm is 52mm and the base height is 48mm - Worker hourly output
A worker makes 12 furs in 12 hours. One truck has 20 m³. The price for the application is 2.45 euros/m³. What will be the hourly output in euros?
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