Math practice for 13 year olds - page 211 of 413

Number of problems found: 8260

Spoon volume calculation
The spoon has the shape of half a spherical surface with a radius of 50 mm. What volume of fluid does it fit when filled to the brim?
Pool water height
82 hl of water per hour flows into the empty cylinder-shaped pool with a bottom diameter of 7.5 m. How high will the pool be filled if the water has flowed in for 4 hours?
Tiles
The pupils of the building school have to calculate how many roof tiles they will need to cover the roof of the house in the shape of two rectangles measuring 10 x 7.2 m. One roof tile covers a rectangular area of 22 cm x 32 cm. How many tiles will they n
Equation solving
Solve the equation: 5 / (x-4) - 2 / (4x-16) = - 7
Salary ratio change
They changed my mother's original salary to 750 euros in a 6:5 ratio. How many euros is he earning now?
Water ball diameter
The water ball has a volume of 32,500 m³. How big is its diameter?
Combinations and eggs
You have colored 4 red eggs, 3 green, 4 yellow, 5 blue, and 5 white. A caroler stops by you, and you decide to give him three eggs of different colors. How many options (different color combinations) do you have for gifting a caroler?
The shooter
The shooter heard the bullet's impact on the target one second after the shot. The bullet was moving at an average speed of 500 m/s. Calculate with the speed of sound of 340 m/s. Determine the distance of the target.
Base of an isosceles triangle
Calculate the size of the base of an isosceles triangle; the height is 5 cm, and the arm's length is 6.5 cm. What is the perimeter of this triangle?
Identical line
In which triangles is the line identical with the height?
Lotto winnings distribution
Three friends submitted a lotto for €600. Karel gave €250, Laco €200, and Josef gave the rest. They won €15,000 and shared the winnings in the same proportion as they contributed to the sport. How many euros did Josef receive?
Hectares of forest
Twelve workers plant 24 ha of forest in 6 days. How many days will it take 15 workers to plant the same area, and how many days will it take 12 workers?
Anniversary age calculation
Mr. and Mrs. Smith announce the celebration of their 190th anniversary - that's how many years they've been together this year. How old are Mr. Smith and Mrs. Smith if we know that Mr. Smith is nine years older than Mrs. Smith?
Height of the cuboid
Cuboid with a rectangular base, measuring 3 cm and 4 cm diagonal, has a body 13 centimeters long. What is the height of the cuboid?
Pool filling calculation
The 300 liters per minute water starts to flow into the empty pool. We will fill the pool in 5 hours. How long would it take to fill a pool with a more powerful 750 L pump per minute?
Earnings hour division
Two workers worked on a joint task: One worked 36 hours and the other 40 hours. Earnings of 11400 are divided by the ratio of hours worked. How much did everyone get?
Material consumption
The sphere-shaped reservoir has a volume of 282 hl. Calculate the material consumption in m² for its production, assuming 8% for joints and waste, and round the final result to the nearest integers.
The regular
The regular quadrilateral pyramid has a volume of 24 dm³ and a height of 45 cm. Calculate its surface.
Salary reduction calculation
The employer reduced Mr. Mak's salary by 4:5. If he received € 720 in his account, how much did he initially earn?
Trapezoid area perimeter
Calculate the area and perimeter of the building plot in the shape of an isosceles trapezoid with a base of 120 m, 95 m, and a height of 50 m.

Do you have unsolved math question and you need help? Ask a question, and we will try to solve it. We solve math question.