Maths practice for 12-year-olds - page 172 of 347

Number of problems found: 6923

Trapezoid - construction
Construct a trapezoid KLMN, where: k = 9 cm, l = 4 cm, m = 5 cm and angle α = 45°
Hexagonal prism
Calculate the volume and surface of a regular hexagonal prism with the edge of the base a = 6 cm with the corresponding height v1 = 5.2 cm and the height of the prism h = 1 dm.
Fabric width consumption
The vest consumes 170 cm of fabric with a width of 140 cm. What is the consumption of a material that is 150 cm wide?
Quadrilateral pyramid
Calculate the volume of a regular quadrilateral pyramid, given: 1) a = 3.5 m; v1 = 24 dm Express the volume in m³ and round to 1 decimal place 2) a = 1.6 dm; v2 = 295 mm Calculate the volume in cm³ and round to 1 decimal place Solution entry: 1) entry 2)
Calculate sphere
Calculate the surface area and mass of a sphere whose volume is 707.54 cm³, made of a material with a density of 7.8 g/cm³.
Barrel and buckets
The barrel has a base diameter of 6 dm and a height of 1.2 m. How many 5-liter buckets will we fill it to 3/4 of its height?
Mirror reflection count
If I have two plane mirrors at a distance of about 10 cm, how many times will the displayed object (pin) appear to me?
Used cars
Peter plans to buy a used car: The first car was a Renault Espace 2.0 dCi 16 V Dynamique 2006, which cost 2000 euros. It is 14 years old and has a combined diesel consumption of 8 liters. / 100 km. Diesel costs 1.1 euros/liter. How much will the car cost
Round table
The round table has a diameter of 78 cm. A tablecloth should be sewn on it, extending around the table by 10 cm. How many centimeters of ribbons need to be bought for edging?
Hall painting time
The hall has dimensions of 60 m, 28 m, and a height of 3 m. How many hours will it take to paint it if it takes 3 minutes to paint 1 square meter? The walls and ceiling are painted, and the windows take up 1/3 of the total area that needs to be painted.
Glove order
Four apprentices worked on a glove order for 20 days. How long would it take for eight apprentices to complete the contract in the same job?
Cube diagonal calculation
Calculate the length of the wall diagonal of a cube with a volume of 7.40 dm cubic. Express the result to the nearest millimeter.
Lathe production calculation
The lathe machined 27 parts in 9 minutes. How many of them work at the same rate per hour?
Map scale determination
Determine the map's scale if the 1.6 km, 2.4 km, and 2.7 km triangle-shaped forests are drawn on the map as a triangle with sides of 32 mm, 48 mm, and 54 mm.
Flowerbed transplant
In the middle of the square, they created a flower bed in the shape of an isosceles trapezoid. The parallel sides are 12 m and 8 m long. The bed is 6 m wide. How many flower transplants do they need to plant a flower bed if 4 dm² of space must be counted
Grass seed calculation
How many g of grass seed do we have to buy in the eight-square garden with a side of 20 m if we need 100 g of seed per 8 m²?
Production people
Calculate how many people are in production, if there are 1/5 workers on the morning shift, the afternoon shift has 3/10, and 50 people will join the night shift.
Going to paint
The dimensions of the room are 3.8 and 3.4 m. The height is 2.6 m. The doors and windows together have 3.5 m². We are going to paint. The first coat with white basic we apply on the walls and ceiling. We paint with colour only the walls. Calculate how muc
Brass sphere
Find the weight of a brass ball with an outer radius of 12 cm and a wall thickness of 20 mm if the brass's density is 8.5 g/cm³.
Thousand balls
We must create a thousand balls from a sphere with a diameter of 1 m. What will be their radius?

Do you have homework that you need help solving? Ask a question, and we will try to solve it. Solving math problems.