Math practice for 13 year olds - page 342 of 424
Number of problems found: 8462
- Separated 3495
14% of separated waste in Slovakia in 2007 consisted of plastics. The glass managed to separate twice as much. What% of separated waste was glass? What% of separated waste was another waste?
- Together 3491
One painter would paint the school in 15 days. Together with the second painter, they painted the school in 6 days. In how many days the second painter would have painted the school himself?
- Triangular prism
The perpendicular triangular prism is a right triangle with a 5 cm leg. The prism's largest wall area is 130 cm2, and the body height is 10 cm. Calculate the body volume.
- Infinitely 3489
The solution to the equation 3x = 8x is a / no real number b / x = 8/3 c / x = 3/8 d / x = 0 e / infinitely many solutions
- Determined 3488
Find out if there is a triangle whose two sides are 5 cm and 8 cm long and the middle bar determined by their centers is 1.5 cm long.
- Grandmother
Grandmother wants to give the candies to grandchildren so that when she gives five candy everyone, three are missing, and when she gives four candies, 3 are surplus. How many grandchildren have a grandmother, and how many sweets do they have?
- Whitewashed 3483
The pool is in the shape of a vertical prism with a bottom in the shape of an isosceles trapezoid with dimensions of the bases of the trapezoid 10m and 18m, and arms 7m are 2m deep. During spring cleaning, the bottom and walls of the pool must be whitewas
- Toothpaste 3479
A full tube of toothpaste is enough for one family member for six weeks. How long will three family members last?
- Rectangular 3478
A segment AB is drawn in the rectangular coordinate system with endpoints A [1;6] and B [5;2]. The center symmetry is the origin of the coordinate system. Find the coordinates of the center of this segment in this symmetry projection.
- Twenty-seven 3476
Twenty-seven workers did the work in 12 days. In how many days would nine workers do the same job?
- Working time
If work is done in 16 days at a 10-hour shift, how many days will it be done at 8-hour shifts?
- Two-meter 3473
A tree with an unknown height casts a shadow 18 m long at a time, while a two-meter pole casts a shadow of 2.4 m. How tall is the tree?
- Evaporating 3472
By evaporating 15 kg of seawater, we get 517.5 g of salt. How much seawater do we need to obtain 3.45 kg of salt?
- Cuboid - edges
The cuboid has dimensions in a ratio of 4:3:5. The shortest edge is 12 cm long. Find: The lengths of the remaining edges The surface of the cuboid The volume of the cuboid
- Cone
Calculate the volume of the rotating cone with a base radius of 26.3 cm and a side 38.4 cm long.
- The factory
The factory ordered 500 hexagonal steel bars in square sections with 25 mm sides. Suppose the steel density is 7,850 kg. m-3, how many cars with a load capacity of 3 tonnes will be needed to move the bars?
- Hexagonal prism
The box of a regular hexagonal prism is 4 cm high, and the lid has sides 20 cm long. How much cardboard is needed to make it? (No part is double)
- Attempts 3460
How many attempts do I need to guess the 3-digit PIN to be sure I can guess it?
- Tributaries 3458
At the swimming pool, they usually use three tributaries with the same power to fill the pool. Then the pool will fill in 5 hours. How many hours less would it take to fill the pool if they added 2 more inlets with the same capacity?
- Two-digit 3456
Write all the two-digit numbers that can be composed of the digit 7,8,9 without repeating the digits. Which ones are divisible b) two, c) three d) six?
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