Maths practice for 12-year-olds - page 200 of 355
Number of problems found: 7083
- Blueberries collecting
Marie collects 2 l of blueberries in 1 hour. She began collecting at 8.00 PM. Joe collects 1.5 l in 1 hour. Peter collects 1 l for 1 hour. They began to gather at 08.30 PM. Together, they collect 10 l. At what time will they all be collected? - Kinetic energy
A car traveling at a speed of 25 km/h increased the speed to a) 75 km/h b) 100 km/h when exiting the highway. How many times has its kinetic energy increased? - Hammer fall height From what height does a hammer weighing 200 kg fall if its initial potential gravity was 6 kJ?
- Eight masons
Eight masons will plaster a wall with an area of 1440 m² in 9 days. They work 8 hours a day. How much area will plaster six masons in 4 hours? - Vehicle meeting calculation
The motorcycle left Děčín at an average speed of 40 km/h. At the same time, a passenger car from Prague drove towards him at an average speed of 80 km/h. The distance from Prague to Děčín is about 100 km. How long and at what distance from Děčín will both - Car cyclist pursuit
Behind a cyclist traveling at an average speed of 20 km/h, he left the same place 2 hours later than a passenger car at an average speed of 60 km/h. How long and at what distance will the passenger car catch up with the cyclists? - Where and when
The truck left Kremnica at 11:00 h at a speed of 60km/h. At 12:30 h, the passenger car started at an average 80km/h speed. How many kilometers from Kremnica will the passenger car reach the truck, and when? - Brothers and sisters
There are 35 children in the class; 23 have a brother, and 27 have a sister. When five children in the class have no brother or sister, how many children have both a brother and a sister? - Tram meeting time
Trams of five lines run at intervals of 5, 8, 10, 12, and 15 minutes. At noon, they left the station at the same time. What time will they meet again? How many times will each tram pass the stop during that time? - Tree inspection calculation
During the inspection of the trees, we found that 1/3 was broken and 2/5 bitten. In the beginning, there were only 40 pieces. How much was planted in total? - Two villages
On the map with a scale of 1:40000 are drawn two villages actually 16 km away. What is their distance on the map? - Circle radius calculation
The area of the two circles is in a 4:9 ratio. The larger circle has a diameter of 18 cm. Calculate the radius of the smaller circle. - Three lines
At 6 AM, three bus lines depart from the station. The first line has an interval of 24 minutes. The second line has an interval of 15 minutes. The third line runs at regular intervals of more than 1 minute. The third line runs at the same time as the firs - Radius
Find the radius of the circle with area S = 200 cm². - Floating of wood - Archimedes law
Wooden balsa block has a density of 200 kg/m³ and a volume of 0.02 m³ floating in alcohol. Alcohol density is 789 kg/m³. What will be the volume of the floating part of a balsa block? - Cheops pyramid
The Pyramid of Cheops is a pyramid with a square base with a side of 233 m and a height of 146.6 m. It is made from limestone with a density of 2.7 g/cm³. Calculate the amount of stone in tons. How many trains with 30 twenty-ton wagons carry the stone? - Number multiplication puzzle
Which number needs to be multiplied by 2 3/4 to get 8 1/3? - Common divisors
Find all common divisors of numbers 30 and 45. - Triangle exterior angle
The interior angles of the triangle are 108 degrees 45 minutes and 51 degrees 19 minutes. Calculate the outside angle at the third vertex. - Grandpa MO Z5–I–5 2019
Grandpa has three apple trees in his garden and a total of 39 apples on them. Apples grow on only eight branches: one apple tree bears two branches, two apple trees bear three branches each. There are different numbers of apples on different branches, but
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