Math practice for 13 year olds - page 198 of 428
Number of problems found: 8555
- Receiving heat
How many degrees Celsius was an iron cylinder weighing 300 g heated in a water bath if it received heat of 7.2 kJ? (specific heat capacity of iron c = 0.46kJ/kg/ºC) - Square side calculation
Calculate the length of the side of the square if the size of the diagonal u = 9.9 cm is entered. - Number sum difference
The sum of 2 numbers, x, and y, is 80, and their difference is 16. Determine the numbers x and y. - Aquarium height calculation
The cuboid-shaped aquarium has the dimensions of the bottom: a = 0.7 m, b = 0.4 m. if it is filled to 90% of its volume and contains 75.6 liters of water? - Tree planting calculation
The tourist section planted 145 trees, 16% more than planned. What was the original plan? - Final price
The bookshop reduced the book's original price of CZK 850 by 20%. It was raised by 20% of the new price in a week. Find the final price of the book. How much percent of the original price of the book is the final price? - Final exam
At the final exam, the student answers from three areas, which are evaluated in a ratio of 1:2:2. What grade will John receive if he replies as follows: 3,1,2. - Banknote distribution
We have the amount of 1,250 euros in banknotes of 100 and 50 euros. We have a total of 17 banknotes. How many are there? - Goat chicken puzzle
There were goats and chickens in the yard. The total number of heads was 15, and the total number of legs was 40. Calculate the number of hens. Every animal has all its legs. - Readers
Readers borrowed 220 books from the library during the first three days. On the second day, readers borrowed half as many books as on the first day and, at the same time, 20 fewer books than on the third day. Depending on the quantity x, express the numbe - The trench
Calculate how many cubic meters of soil need to be removed from the excavation in the shape of an isosceles trapezoid. The top width is 3 meters, the lower width is 1.8 m, the excavation depth is 1 m, and the length is 20 m. - Square and circles
The square in the picture has a side length of a = 20 cm. Circular arcs have centers at the vertices of the square. Calculate the areas of the colored unit. Express area using side a. - Sapling planting calculation
In the forest, there are 84 workers employed in planting saplings. Working 10 hours a day, they would finish the job in 24 days. After 7 days, 14 workers leave. How long will it take the others to finish planting the saplings if they work 12 hours a day f - Pyramid base calculation
The volume of the right 4-side pyramid is 138 m3, and its height is 9m. Calculate the area of the base and the edge of its base. - Cone mesh drawing
Sketch the cone mesh and add the side length, the arc length of the circle, and the circle length to it, if you know: the side length of the cone: s = 51.9 cm cone base circumference = O = 151 mm. - Ointment component ratio
The four-component ointment contains components A, B, C, and D. Components A and B are mixed in a ratio of 1:2, components B and C in a ratio of 3:5, and components B and D in a ratio of 4:3. In what proportion should the pharmacist mix the ointment? - Skirt fabric calculation
They bought fabric to sew a skirt in a tailor's salon. If they sewed skirts 50 cm long, they would sew 70 of them. How many skirts will they sew if they are 70 cm long? - Tractor plowing calculation
Tractor operator Formánek can plow Mr. Kafka's land in 30 hours using a plowing set with a four-blade plow. The tractor driver Divíšek, plowing with a five-blade plow, can plow Kafka's land in 24 hours. In how many hours will the two tractor drivers plow - Cyclist pedestrian pursuit
Behind a pedestrian walking at an average speed of 5 km/h, a cyclist drove from the same place 3 hours later at an average speed of 20 km/h. How long will it take for a cyclist to catch up with a pedestrian? - Toothpaste usage time
The father would use the toothpaste alone for 15 days, the mother for 12 days, and the daughter for ten days. It was used by all three for three days, then only the father and mother. How many days have they used it since the beginning of its use?
Do you have homework that you need help solving? Ask a question, and we will try to solve it. Solving math problems.
