# Expression of a variable from the formula - 7th grade (12y) - math problems

#### Number of problems found: 234

- Cube containers

Replace the two cube-shaped containers with 0.8 dm and 0.6 dm edges with a single cube-shaped one so that it has the same volume as the two original ones together. What is the length of the edge of this cube? - Volume per time

How long does fill take for a pump with a volume flow of 200 l per minute fill a cube-shaped tank up to 75% of its height if the length of the cube edge is 4 m? - Gardens

The area of the square garden is 3/4 of the area of the triangular garden with sides of 80 m, 50 m, 50 m. How many meters of the fence do we need to fence a square garden? - Six painters

Six painters paint an area of 120 m^{2}in 4 hours. How long does it take for 12 painters to paint 480 m^{2}with the same performance? - Thousand balls

We have to create a thousand balls from a sphere with a diameter of 1 m. What will be their radius? - Extending square garden

Mrs. Petrová's garden had the shape of a square with a side length of 15 m. After its enlargement by 64 m^{2}(square), it had the shape of a square again. How many meters has the length of each side of the garden been extended? - Height

The content of the triangle is 35 cm^{2}. The length of the base is 10 cm. Determine the length of the height on the base. - Similar triangles

Triangle A'B'C 'is similar to triangle ABC, whose sides are 5 cm, 8 cm, and 7 cm long. What is the length of the sides of the triangle A'B'C ' if its circumference is 80 cm? - Cylinder container

The cylindrical container with a diameter of 1.8 m contains 2,000 liters of water. How high does the water reach? - Twice of radius

How many times does the surface of a sphere decrease if we reduce its radius twice? - Save trees

25 tons of old paper will save 1,600 trees. How many tons of paper is needed to save the 32 trees in the park? - Aquarium height

How high does the water in the aquarium reach, if there are 36 liters of water in it? The length of the aquarium is 60 cm and the width is 4 dm. - Cube surfce2volume

Calculate the volume of the cube if its surface is 150 cm^{2}. - The cube

The cube has a surface area of 216 dm^{2}. Calculate: a) the content of one wall, b) edge length, c) cube volume. - Quadrilateral prism

The surface of the regular quadrilateral prism is 8800 cm^{2}, the base edge is 20 cm long. Calculate the volume of the prism - Second side

Calculate the length of the other side of the rectangle if its circumference is 60 cm and one side is 10 cm long. - Age of family

The age of father and son is in the ratio 10: 3. The age of the father and daughter is in ratio 5: 2. How old are a father and a son if the daughter is 20? - Interior angles

Calculate the interior angles of a triangle that are in the ratio 2: 3: 4. - The farmer

The farmer calculated that the supply of fodder for his 20 cows was enough for 60 days. He decided to sell 2 cows and a third of the feed. How long will the feed for the rest of the peasant's herd last? - Library

New books were purchased for the library. Five-eighths were professional books, one-fifth were encyclopedias, and 231 books were dictionaries. How many professional books were there?

Do you have an interesting mathematical word problem that you can't solve it? Submit a math problem, and we can try to solve it.