Percentages + surface area - practice problems
Number of problems found: 97
- Perimeter 83259
The perimeter of the four-sided needle is 48 m, and its height is 2.5 m; how much will the sheet metal for this pyramid cost? If 1m² costs €1.5, a 12% loss due to joints and folds is included in the area. - Allowances 82413
The teacher decided to sew covers for the eight-seat blocks in the school library. All cubes are cube-shaped with an edge 40 cm long. How many m² of fabric will the teacher need in total if the blocks are not lined from the bottom, and 5% must be added fo - Calculate 82409
The lamp shade should be formed by the shell of a cone with a base diameter of 48 cm and a side of 32 cm. Calculate how much material will be needed to make it, assuming 8% waste - Percentage 81914
The carpenter worked on a rotary cylinder with a base radius of 2.5 dm and a height of 2 dm. He reduced the radius by 1 cm by uniform grinding, and the height of the cylinder was preserved. Calculate the percentage by which the volume of the cylinder has
- Dimensions 79294
The swimming pool dimensions are as follows: l:w:h = 10:4:1. The pool can hold 625 m³ of water. Calculate how many square meters of tiles need to be purchased for lining the pool walls if we add 5% for waste. - Coverage 71484
The tower's roof is a regular 4-sided pyramid with a height of 4m and an edge of the base of 6m. 25% of the roof covering was found to be damaged. How many square meters of coverage are needed to repair the roof? - Cube-shaped 71414
Mother and daughter Susan are wrapping presents for father. Maťko has a cube-shaped box with dimensions of 9 cm, 3 cm, and 7 cm, and Zuzka has a box in the shape of a cube with an edge length of 3 cm. How many square cm of wrapping paper will they use in - Perpendicular 68194
The closed box has the shape of a perpendicular prism with the base of an equilateral triangle. The edge of the base is 24 cm long, and the height of the box is 0.5 m. Calculate how many square meters of cardboard are needed to make 20 such boxes, assumin - Interested 67344
Monika measured the dimensions of two different milk cartons. One had dimensions of 9*5.8*19.6 cm, the other 9.4*6.3*17.3 cm. She wanted to see if less material was used to make a particular box. Check it out and find out what percentage of material is sa
- Considering 67324
Susan has an old stool - a cube with an edge length of 80 cm. She wants to sew a new cover for her. How many square meters does the fabric consume, considering adding 15% for stitching and folds? - Original 63974
If we reduce the length of the cube edge by 30%, this cube has a reduced surface area of 1176 cm². Find the edge length and volume of the original cube. - The conical roof
The conical roof above the warehouse has a diameter of the lower part (base) d = 11.2 m and a height v = 3.3 m. How many rectangular steel plates with dimensions of 1.4 m and 0.9 m were needed to produce this roof if the seams and waste required an increa - Determine 46401
The volume of the sphere is 20% larger than the volume of the cone. Find its surface if the volume of the cone is 320 cm³. - Rectangular 44951
The surface area of the rectangular plot needs to be increased by 33.7 percent. One dimension was extended by 2.9 percent. By what percentage should the second dimension be increased? Round the result to two decimal places.
- Dimensions 44081
In the form of a pyramid on the house with a square floor plan, the roof has dimensions of 12 x 12 m, with a height of 2 m at the highest point. How much roofing do I need to buy? Count on a 10% reserve. - The roof
The tower's roof has the shape of a regular quadrangular pyramid, the base edge of which is 11 m long, and the side wall of the animal with the base at an angle of 57°. Calculate how much roofing we need to cover the entire roof if we count on 15% waste. - Calculation 43211
The roof is shaped like a hemisphere with a diameter of 8 m. Calculate how much m² of roofing is needed to cover the entire top if we count 15% for waste and residues and round the result to tenths of m². Use the constant pi rounded to two decimal places - Cardboard 37871
The closed cardboard box has the shape of a block measuring 25 cm, 1.2 dm, and 0.5m. How much cardboard is needed to make 20 such boxes? If you need to add 5% per bend. - Block-shaped 37841
Calculate how much sheet metal is needed to make a closed block-shaped container with dimensions of 2 m, 7 m, and 9 m if we must add 12% to the welds.
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