Math practice for 13 year olds - page 204 of 424
Number of problems found: 8469
- Ditch
The excavator dug 40% of the excavation in 2 hours and 20 minutes. How long does it take him to dig the whole ditch?
- Millimeter 24231
Calculate the length of the wall diagonal of a cube with a volume of 7.40 square meters. Express the result to the nearest millimeter.
- Body diagonal
Calculate the surface area, volume, and length of the body diagonal of a cube with an edge length of 4 dm.
- Sooner 24191
If I read a book at a rate of 15 pages a day, I will read it three days sooner than if I read it at a rate of 10 pages a day. If I read at a rate of 6 pages daily, I'll read a book.
- Quadrilateral prism
Calculate the volume of a quadrilateral prism whose base is an isosceles trapezoid with bases 10 cm and 4 cm, 6 cm apart. The height of the prism is 25 cm. How could the surface area be calculated?
- Percentage 24151
In a square garden with a side length of 12 m, there are two circular flower beds with a diameter of 4 m, and the rest is grass. Determine the area that is overgrown with grass. What percentage of the garden is occupied by flower beds?
- The convoy
During a military exercise, the convoy left the camp at 5 hours at a speed of 40 km/h. Half an hour later, the commander sent a motorcycle clutch at a speed of 70 km/h. How long before the motorcycle clutch reaches the column?
- Assignment 24071
1) Adam lives 4 kilometers from Eve. At the same time, he leaves for a meeting. Adam at a speed of 6 km/h and Eve at a speed of 4 km/h. How long will it take them to meet, and how many kilometers will Adam walk? 2) It was the same assignment, but Eva did
- Quadrilateral pyramid
Calculate the surface of a quadrilateral pyramid with a rectangular base, dimensions a = 8 cm, b = 6 cm, and height H = 10 cm.
- Interior angles
In a quadrilateral ABCD, whose vertices lie on some circle, the angle at vertex A is 58 degrees, and the angle at vertex B is 134 degrees. Calculate the sizes of the remaining interior angles.
- Side lengths
In the triangle ABC, the height to side a is 6cm. The height to side b is equal to 9 cm. Side "a" is 4 cm longer than side "b". Calculate the side lengths a, b.
- Production 24021
The plant has to complete the order in 40 working days. Production takes place in two workshops. In the first one, there are more workers; therefore, they would complete the order themselves in 70 working days. In the second workshop, they would complete
- Reconstructing 23991
Three groups take turns reconstructing one piece of highway. The first group would finish the job themselves in 40 working days. The second group is in 24 working days, and the third group is in 30 working days. How many days do you do it together?
- Three-fifths 23961
Three-fifths of the orchard trees are apple trees. One-third are cherry trees. The remaining five trees are pear trees. How many trees are in total growth in the orchard?
- Observation tower
The observation tower has a height of 105 m above sea level. The ship is aimed at a depth angle of 1° 49' from the tower. How far is the ship from the base of the tower?
- Pentagonal prism
The regular pentagonal prism is 10 cm high. The radius of the circle of the described base is 8 cm. Calculate the volume and surface area of the prism.
- The shadow
The shadow of a 1 m high pole thrown on a horizontal plane is 0.8 m long. At the same time, the shadow of a tree thrown on a horizontal plane is 6.4 m. Determine the height of the tree.
- Diameters: 23901
When paying, we use euro coins with the following diameters: The 10-cent coin has a diameter of 19.75 mm. The 20-cent coin has a diameter of 22.25 mm. The 50-cent coin has a diameter of 24.25 mm. Find out in what ratio the diameters of these coins are.
- Quadrilateral 23891
A cylinder with the maximum possible base was ground from a wooden regular quadrilateral prism (edge 2.8 cm, height 7.5 cm). What percentage of the material was wasted as waste? What percentage would it be if the height of the prism were twice as large?
- 3 pupils
Three pupils cleaned 10 meters of the stream in 1 hour. How many meters of the stream will clean 18 students in 4 hours?
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