Math practice for 13 year olds - page 58 of 351
Number of problems found: 7015
- Equilateral 81222
A sphere is inscribed in an equilateral cone with a base diameter of 12 cm. Calculate the volume of both bodies. What percentage of the volume of the cone is filled by the inscribed sphere? - Denarii 81214
Two men talk about how much money each has. The first says to the second: If you give me 12 denarii, we will both have the same. "Second branch: If you give me 12 denarii, I will have ten times more than you. How many denarii did each of them have? - Millimeter 81208
A cylinder has the same diameter as its height. Calculate these data if the surface is 200 cm square. Report the results to the nearest millimeter. - Correspond 81207 Zuzana, Anna, and Eliška receive pocket money every month. They donated part - Zuzana 40%, Anna 50% and Eliška CZK 195. If we add up all 3 amounts and divide the sum by 3, the result will correspond to 4/9 of the pocket money of each of the girls. What is
- Airplane 81200
Two points are at a distance of 1840 km. An airplane departs from A at 7:00 a.m. and flies at an average speed of 50 km/h faster than another airplane departs from B at 8:00 a.m. At what distance from A do they meet at 9:00? - Millimeter 81160
Calculate the length of the side of the cone; they rounded the result to tenths of a millimeter. If you know: radius 24 mm and height 46 mm - Together 81151
Matěj has 2 more marbles than three times the number of marbles that Lojza. Both together have 18 balls. How many marbles does Lojza have? - Right-angled 81150
In the right-angled triangle ABC (the right angle at vertex C), the angle ratio is α : β = 5 : 3. Calculate the sizes of these angles and convert them to degrees and minutes (e.g., 45°20') - Father 81149
The father is older than the son by the ratio of 5:2. Dad is older than 33. How old are they both?
- Quadrilateral and angles
In a quadrilateral, angle α is twice as large as angle β. Angle γ is 80% of angle α, and angle δ is 30° greater than angle α. Determine the angles of this quadrilateral. - Percentage - fence
We are painting a wooden fence. On the first day, we painted one-half of the fence. The next day, we painted half of the remaining part. On the third day, again, half of the remaining part. After the third painting, we had 12.5 meters of unpainted fence l - Toothpaste 81127
How long will the roll of toothpaste be extruded from the tube if the volume of the toothpaste is 100 ml and the diameter of the opening is 8 mm? - Processed 81125
The total number of orders processed in the courier office in five days is 10, 6, 8, 7, 9, then the total of Squares is ... - Observations 81124
The number of observations is 24, and the value of the mean is 28, then the sum of all the values is ...
- Revolutions 81118
1. A disc makes 15 revolutions per minute. Determine his angular speed and the boy's speed on the seat that describes a circle with a radius of 5 m. 2. The grinding wheel rotates at 600 revolutions per minute. Determine the period and angular velocity. Th - Probability 81117
Martin forgot the 4-digit PIN, and he remembered the first three numbers. The fourth number is odd. What is the probability in % that he will be able to determine the PIN? He has only one attempt. - Twenty-five 81116
Twenty-five pencils were bought as prizes in the school competition. The more expensive pencils were for 20 CZK, the cheaper ones for 15 CZK. The entire amount paid was 455 CZK. How many are there? - Chocolate 81103
I paid 36 crowns for butter and chocolate. Butter was CZK 6 more expensive than chocolate. How much did the chocolate cost? - Painters 81101
Four painters painted the house in 14 days. How long will it take if 2 more come to help after 5 days?
The area of the rectangle is 81.25 cm². If we increase its length by 5 mm, its area increases by 4%. Determine its dimensions.Do you have homework that you need help solving? Ask a question, and we will try to solve it. Solving math problems.
